1
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Roy P, Sardjan AS, Browne WR, Feringa BL, Meech SR. Excited State Dynamics in Unidirectional Photochemical Molecular Motors. J Am Chem Soc 2024; 146:12255-12270. [PMID: 38656968 DOI: 10.1021/jacs.4c01019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Unidirectional photochemically driven molecular motors (PMMs) convert the energy of absorbed light into continuous rotational motion. As such they are key components in the design of molecular machines. The prototypical and most widely employed class of PMMs is the overcrowded alkenes, where rotational motion is driven by successive photoisomerization and thermal helix inversion steps. The efficiency of such PMMs depends upon the speed of rotation, determined by the rate of ground state thermal helix inversion, and the quantum yield of photoisomerization, which is dependent on the excited state energy landscape. The former has been optimized by synthetic modification across three generations of overcrowded alkene PMMs. These improvements have often been at the expense of photoisomerization yield, where there remains room for improvement. In this perspective we review the application of ultrafast spectroscopy to characterize the excited state dynamics in PMMs. These measurements lead to a general mechanism for all generations of PMMs, involving subpicosecond decay of a Franck-Condon excited state to populate a dark excited state which decays within picoseconds via conical intersections with the electronic ground state. The model is discussed in the context of excited state dynamics calculations. Studies of PMM photochemical dynamics as a function of solvent suggest exploitation of intramolecular charge transfer and solvent polarity as a route to controlling photoisomerization yield. A test of these ideas for a first generation motor reveals a high degree of solvent control over isomerization yield. These results suggest a pathway to fine control over the performance of future PMMs.
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Affiliation(s)
- Palas Roy
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
- School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, Odisha 752050, India
| | - Andy S Sardjan
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, 9747AG Groningen, The Netherlands
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, 9747AG Groningen, The Netherlands
| | - Ben L Feringa
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, 9747AG Groningen, The Netherlands
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K
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2
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Sheng J, Danowski W, Sardjan AS, Hou J, Crespi S, Ryabchun A, Domínguez MP, Jan Buma W, Browne WR, Feringa BL. Formylation boosts the performance of light-driven overcrowded alkene-derived rotary molecular motors. Nat Chem 2024:10.1038/s41557-024-01521-0. [PMID: 38671301 DOI: 10.1038/s41557-024-01521-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 03/26/2024] [Indexed: 04/28/2024]
Abstract
Artificial molecular motors and machines constitute a critical element in the transition from individual molecular motion to the creation of collective dynamic molecular systems and responsive materials. The design of artificial light-driven molecular motors operating with high efficiency and selectivity constitutes an ongoing fundamental challenge. Here we present a highly versatile synthetic approach based on Rieche formylation that boosts the quantum yield of the forward photoisomerization reaction while reaching near-perfect selectivity in the steps involved in the unidirectional rotary cycle and drastically reducing competing photoreactions. This motor is readily accessible in its enantiopure form and operates with nearly quantitative photoconversions. It can easily be functionalized further and outperforms its direct predecessor as a reconfigurable chiral dopant in cholesteric liquid crystal materials.
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Affiliation(s)
- Jinyu Sheng
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Wojciech Danowski
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
- Institute of Supramolecular Science and Engineering (ISIS), Université de Strasbourg, CNRS, Strasbourg, France
- Faculty of Chemistry, University of Warsaw, Warsaw, Poland
| | - Andy S Sardjan
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Jiaxin Hou
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Stefano Crespi
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
- Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala, Sweden
| | - Alexander Ryabchun
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | | | - Wybren Jan Buma
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, Amsterdam, The Netherlands
- Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Nijmegen, The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
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3
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Roy P, Sardjan AS, Danowski W, Browne WR, Feringa BL, Meech SR. Control of Photoconversion Yield in Unidirectional Photomolecular Motors by Push-Pull Substituents. J Am Chem Soc 2023; 145:19849-19855. [PMID: 37646616 PMCID: PMC10510317 DOI: 10.1021/jacs.3c06070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Indexed: 09/01/2023]
Abstract
Molecular motors based on the overcrowded alkene motif convert light energy into unidirectional mechanical motion through an excited state isomerization reaction. The realization of experimental control over conversion efficiency in these molecular motors is an important goal. Here, we combine the synthesis of a novel "push-pull" overcrowded alkene motor with photophysical characterization by steady state and ultrafast time-resolved electronic spectroscopy. We show that tuning of the charge transfer character in the excited state has a dramatic effect on the photoisomerization yield, enhancing it to near unity in nonpolar solvents while largely suppressing it in polar solvents. This behavior is explained through reference to solvent- and substituent-dependent potential energy surfaces and their effect on conical intersections to the ground state. These observations offer new routes to the fine control of motor efficiency and introduce additional degrees of freedom in the synthesis and exploitation of light-driven molecular motors.
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Affiliation(s)
- Palas Roy
- School
of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K.
- School
of Basic Sciences, Indian Institute of Technology
Bhubaneswar, Bhubaneswar, Odisha 752050, India
| | - Andy S. Sardjan
- Molecular
Inorganic Chemistry, Stratingh Institute
for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Wojciech Danowski
- Centre
for Systems Chemistry, Stratingh Institute
for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
- University
of Strasbourg, CNRS, ISIS UMR 7006, 8 allée Gaspard Monge, F-67000 Strasbourg, France
| | - Wesley R. Browne
- Molecular
Inorganic Chemistry, Stratingh Institute
for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Ben L. Feringa
- Centre
for Systems Chemistry, Stratingh Institute
for Chemistry, University of Groningen, 9747 AG Groningen, The Netherlands
| | - Stephen R. Meech
- School
of Chemistry, University of East Anglia, Norwich NR4 7TJ, U.K.
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4
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Klement WJN, Steen JD, Browne WR. Selective Analysis of Redox Processes at the Electrode Interface with Time-Resolved Raman Spectroscopy. Langmuir 2023. [PMID: 37477006 PMCID: PMC10399290 DOI: 10.1021/acs.langmuir.3c00633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Electrochemistry and electrochemical reactions are increasingly important in the transition to a sustainable chemical industry. The electron transfer that drives such reactions takes place within nanometers of the electrode surface, and follow-up chemical reactions take place within the diffusion layer. Hence, understanding electrochemical reactions requires time-, potential-, and spatially resolved analysis. The confocal nature of Raman spectroscopy provides high spatial resolution, in addition to detailed information on molecular structure. The intrinsic weakness of nonresonant Raman scattering, however, is not sensitive enough for relatively minor changes to the solution resulting from reactions at the electrode interface. Indeed, the limit of detection is typically well above the concentrations used in electrochemical studies. Here, we show that surface-enhanced Raman scattering (SERS) and resonance Raman (rR) spectroscopy allow for spatially and time-resolved analysis of solution composition at (<1-2 nm) and near (within 5 μm) the electrode surface, respectively, in a selective manner for species present at low (<1 mM) concentrations. We show changes in concentration of species at the electrode surface, without the need for labels, specific adsorption, or resonance enhancement, using a SERS-active gold electrode prepared readily by electrochemical surface roughening. A combination of smooth and roughened gold electrodes is used to distinguish between surface and resonance enhancement using the well-known redox couples ferrocene and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). We discuss the impact of specific adsorption on the spectral analysis with the ruthenium(II) polypyridyl complex, [Ru(bpy)3]2+. The dual function of the electrode (surface enhancement and electron transfer) in the analysis of solution processes is demonstrated with the reversible oxidation of TMA (4,N,N-trimethylaniline), where transient soluble species are identified in real time, with rapid spectral acquisition, making use of localized enhancement. We anticipate that this approach will find use in elucidating electro(catalytic) reactions at electrode interfaces.
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Affiliation(s)
- W J Niels Klement
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 Groningen, AG, The Netherlands
- Pharmaceutical Analysis, Groningen Research Institute of Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9700 Groningen, AD, The Netherlands
| | - Jorn D Steen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 Groningen, AG, The Netherlands
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 Groningen, AG, The Netherlands
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5
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Siebe HS, Sardjan AS, Maßmann SC, Flapper J, van den Berg KJ, Eisink NNHM, Kentgens APM, Feringa BL, Kumar A, Browne WR. Formation of substituted dioxanes in the oxidation of gum arabic with periodate. Green Chem 2023; 25:4058-4066. [PMID: 37223211 PMCID: PMC10202368 DOI: 10.1039/d2gc04923f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 04/24/2023] [Indexed: 05/25/2023]
Abstract
Renewable polysaccharide feedstocks are of interest in bio-based food packaging, coatings and hydrogels. Their physical properties often need to be tuned by chemical modification, e.g. by oxidation using periodate, to introduce carboxylic acid, ketone or aldehyde functional groups. The reproducibility required for application on an industrial scale, however, is challenged by uncertainty about the composition of product mixtures obtained and of the precise structural changes that the reaction with periodate induces. Here, we show that despite the structural diversity of gum arabic, primarily rhamnose and arabinose subunits undergo oxidation, whereas (in-chain) galacturonic acids are unreactive towards periodate. Using model sugars, we show that periodate preferentially oxidises the anti 1,2-diols in the rhamnopyranoside monosaccharides present as terminal groups in the biopolymer. While formally oxidation of vicinal diols results in the formation of two aldehyde groups, only traces of aldehydes are observed in solution, with the main final products obtained being substituted dioxanes, both in solution and in the solid state. The substituted dioxanes form most likely by the intramolecular reaction of one aldehyde with a nearby hydroxyl group, followed by hydration of the remaining aldehyde to form a geminal diol. The absence of significant amounts of aldehyde functional groups in the modified polymer impacts crosslinking strategies currently attempted in the preparation of renewable polysaccharide-based materials.
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Affiliation(s)
- Harmke S Siebe
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Andy S Sardjan
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Sarina C Maßmann
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Jitte Flapper
- Akzo Nobel Decorative Coatings BV Rijksstraatweg 31 Sassenheim 2171 AJ The Netherlands
| | | | - Niek N H M Eisink
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Arno P M Kentgens
- Magnetic Resonance Research Center, Institute for Molecules and Materials, Radboud University 6525 AJ Nijmegen The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Akshay Kumar
- Magnetic Resonance Research Center, Institute for Molecules and Materials, Radboud University 6525 AJ Nijmegen The Netherlands
- Dutch Polymer Institute (DPI) P.O. Box 902 5600 AX Eindhoven The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
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6
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Roy P, Browne WR, Feringa BL, Meech SR. Ultrafast motion in a third generation photomolecular motor. Nat Commun 2023; 14:1253. [PMID: 36878920 PMCID: PMC9988961 DOI: 10.1038/s41467-023-36777-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 02/13/2023] [Indexed: 03/08/2023] Open
Abstract
Controlling molecular translation at the nanoscale is a key objective for development of synthetic molecular machines. Recently developed third generation photochemically driven molecular motors (3GMs), comprising pairs of overcrowded alkenes capable of cooperative unidirectional rotation offer the possibility of converting light energy into translational motion. Further development of 3GMs demands detailed understanding of their excited state dynamics. Here we use time-resolved absorption and emission to track population and coherence dynamics in a 3GM. Femtosecond stimulated Raman reveals real-time structural dynamics as the excited state evolves from a Franck-Condon bright-state through weakly-emissive dark-state to the metastable product, yielding new insight into the reaction coordinate. Solvent polarity modifies the photoconversion efficiency suggesting charge transfer character in the dark-state. The enhanced quantum yield correlates with suppression of a low-frequency flapping motion in the excited state. This detailed characterization facilitates development of 3GMs, suggesting exploitation of medium and substituent effects to modulate motor efficiency.
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Affiliation(s)
- Palas Roy
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom.,School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Argul, Odisha, 752050, India
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands.
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, United Kingdom.
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7
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Neill JS, Boyle NM, Marques Passo T, Heintz K, Browne WR, Quilty B, Pryce MT. Photophysical and electrochemical properties of meso-tetrathien-2’-yl porphyrins compared to meso-tetraphenylporphyrin. J Photochem Photobiol A Chem 2023. [DOI: 10.1016/j.jphotochem.2023.114573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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8
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Steen JD, Volker A, Duijnstee DR, Sardjan AS, Browne WR. pH-Induced Changes in the SERS Spectrum of Thiophenol at Gold Electrodes during Cyclic Voltammetry. J Phys Chem C Nanomater Interfaces 2022; 126:7680-7687. [PMID: 35558822 PMCID: PMC9082592 DOI: 10.1021/acs.jpcc.2c00416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 03/23/2022] [Indexed: 06/15/2023]
Abstract
Thiophenol is a model compound used in the study of self-assembly of arylthiols on gold surfaces. In particular, changes in the surface-enhanced Raman scattering (SERS) spectra of these self-assembled monolayers (SAMs) with a change of conditions have been ascribed to, for example, differences in orientation with respect to the surface, protonation state, and electrode potential. Here, we show that potential-induced changes in the SERS spectra of SAMs of thiophenol on electrochemically roughened gold surfaces can be due to local pH changes at the electrode. The changes observed during the potential step and cyclic voltammetry experiments are identical to those induced by acid-base switching experiments in a protic solvent. The data indicate that the potential-dependent spectral changes, assigned earlier to changes in molecular orientation with respect to the surface, can be ascribed to changes in the pH locally at the electrode. The pH at the electrode can change as much as several pH units during electrochemical measurements that reach positive potentials where oxidation of adventitious water can occur. Furthermore, once perturbed by applying positive potentials, the pH at the electrode takes considerable time to recover to that of the bulk solution. It is noted that the changes in pH even during cyclic voltammetry in organic solvents can be equivalent to the addition of strong acids, such as CF3SO3H, and such effects should be considered in the study of the redox chemistry of pH-sensitive redox systems and potential-dependent SERS in particular.
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9
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Simeth NA, de Mendoza P, Dubach VRA, Stuart MCA, Smith JW, Kudernac T, Browne WR, Feringa BL. Photoswitchable architecture transformation of a DNA-hybrid assembly at the microscopic and macroscopic scale. Chem Sci 2022; 13:3263-3272. [PMID: 35414864 PMCID: PMC8926171 DOI: 10.1039/d1sc06490h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Accepted: 02/16/2022] [Indexed: 01/01/2023] Open
Abstract
Molecular recognition-driven self-assembly employing single-stranded DNA (ssDNA) as a template is a promising approach to access complex architectures from simple building blocks. Oligonucleotide-based nanotechnology and soft-materials benefit from the high information storage density, self-correction, and memory function of DNA. Here we control these beneficial properties with light in a photoresponsive biohybrid hydrogel, adding an extra level of function to the system. An ssDNA template was combined with a complementary photo-responsive unit to reversibly switch between various functional states of the supramolecular assembly using a combination of light and heat. We studied the structural response of the hydrogel at both the microscopic and macroscopic scale using a combination of UV-vis absorption and CD spectroscopy, as well as fluorescence, transmission electron, and atomic force microscopy. The hydrogels grown from these supramolecular self-assembly systems show remarkable shape-memory properties and imprinting shape-behavior while the macroscopic shape of the materials obtained can be further manipulated by irradiation. Molecular recognition-driven self-assembly employing single-stranded DNA (ssDNA) as a template is a promising approach to access complex architectures from simple building blocks.![]()
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Affiliation(s)
- Nadja A Simeth
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Paula de Mendoza
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Victor R A Dubach
- Groningen Biomolecular Sciences and Biotechnology, Faculty for Science and Engineering, University of Groningen Nijenborgh 7 9747 AG Groningen The Netherlands
| | - Marc C A Stuart
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands .,Groningen Biomolecular Sciences and Biotechnology, Faculty for Science and Engineering, University of Groningen Nijenborgh 7 9747 AG Groningen The Netherlands
| | - Julien W Smith
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Tibor Kudernac
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, Faculty for Science and Engineering, University of Groningen Nijenborgh 4 9747 AG Groningen The Netherlands
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10
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Yao C, Lin H, Daly B, Xu Y, Singh W, Gunaratne HQN, Browne WR, Bell SEJ, Nockemann P, Huang M, Kavanagh P, de Silva AP. Taming Tris(bipyridine)ruthenium(II) and Its Reactions in Water by Capture/Release with Shape-Switchable Symmetry-Matched Cyclophanes. J Am Chem Soc 2022; 144:4977-4988. [PMID: 35274938 PMCID: PMC9097486 DOI: 10.1021/jacs.1c13028] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
![]()
Electron/proton
transfers in water proceeding from ground/excited
states are the elementary reactions of chemistry. These reactions
of an iconic class of molecules—polypyridineRu(II)—are
now controlled by capturing or releasing three of them with hosts
that are shape-switchable. Reversible erection or collapse of the
host walls allows such switchability. Some reaction rates are suppressed
by factors of up to 120 by inclusive binding of the metal complexes.
This puts nanometric coordination chemistry in a box that can be open
or shut as necessary. Such second-sphere complexation can allow considerable
control to be exerted on photocatalysis, electrocatalysis, and luminescent
sensing involving polypyridineRu(II) compounds. The capturing states
of hosts are symmetry-matched to guests for selective binding and
display submicromolar affinities. A perching complex, which is an
intermediate state between capturing and releasing states, is also
demonstrated.
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Affiliation(s)
- Chaoyi Yao
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Hongyu Lin
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Brian Daly
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Yikai Xu
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Warispreet Singh
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland.,Hub for Biotechnology in the Built Environment, Northumbria University, Newcastle upon Tyne NE1 8ST, U.K
| | - H Q Nimal Gunaratne
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, FSE, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Steven E J Bell
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Peter Nockemann
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Meilan Huang
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - Paul Kavanagh
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
| | - A Prasanna de Silva
- School of Chemistry and Chemical Engineering, Queen's University, Belfast BT9 5AG, Northern Ireland
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11
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Abstract
Herein, we show that the photoactive complexes [(Cp)Fe(arene)]+ (Cp = cyclopentadienyl; arene = C6H6, C6H5Me) act as latent catalysts that allow for photochemical control over the onset of alkyd paint curing, without the need for antiskinning agents such as the volatile 2-butanone oxime normally used to prevent curing during paint storage. The highly soluble neutral complexes [(Cp)Fe(Ch)] and [(Cp)Fe(Ch')] (Ch = cyclohexadienyl, Ch' = methylcyclohexadienyl) readily convert to the photoactive complexes [(Cp)Fe(arene)]+ upon oxidation in alkyd, allowing the latter to be dosed in a wide range of concentrations. Infrared and Raman studies show similar spectral changes of the alkyd paint matrix as have been observed in alkyd curing mediated by well-known, industrially applied cobalt- and manganese-based catalyst Co(neodecanoate)2 and [(Me3TACN)2Mn2(μ-OOCR)3](OOCR). The [(Cp)Fe(Ch)]/[(Cp)Fe(arene)]+ system performs equally well as these cobalt- and manganese-based catalysts in terms of drying time and outperform the manganese catalyst by showing a hardness development (increase) similar to that of the cobalt-based catalyst. Based on electron paramagnetic resonance and light-activity studies, we propose that photolysis of [(Cp)Fe(arene)]+ generates short-lived active FeII species, explaining the desired latency. The [(Cp)Fe(Ch)]/[(Cp)Fe(arene)]+ alkyd curing systems presented herein are unique examples of intrinsically latent paint curing catalysts that (1) are based on an abundant and harmless transition metal (Fe), (2) do not require any antiskinning agents, and (3) show favorable performance in terms of drying times and hardness development.
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Affiliation(s)
- Johan Bootsma
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis Group, Van ’t Hoff
Institute for Molecular Sciences, University
of Amsterdam, Science
Park 904, 1098 XH Amsterdam, The Netherlands
| | - Wesley R. Browne
- Molecular
Inorganic Chemistry group, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Jitte Flapper
- Akzo
Nobel Decorative Coatings B.V., Rijksstraatweg 31, 2171 AJ Sassenheim, The Netherlands
| | - Bas de Bruin
- Homogeneous,
Supramolecular and Bio-Inspired Catalysis Group, Van ’t Hoff
Institute for Molecular Sciences, University
of Amsterdam, Science
Park 904, 1098 XH Amsterdam, The Netherlands
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12
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Zhang Q, Crespi S, Toyoda R, Costil R, Browne WR, Qu DH, Tian H, Feringa BL. Stereodivergent Chirality Transfer by Noncovalent Control of Disulfide Bonds. J Am Chem Soc 2022; 144:4376-4382. [PMID: 35120292 PMCID: PMC8931715 DOI: 10.1021/jacs.1c10000] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
![]()
Controlling dynamic
stereochemistry is an important challenge,
as it is not only inherent to protein structure and function but often
governs supramolecular systems and self-assembly. Typically, disulfide
bonds exhibit stereodivergent behavior in proteins; however, how chiral
information is transmitted to disulfide bonds remains unclear. Here,
we report that hydrogen bonds are essential in the control of disulfide
chirality and enable stereodivergent chirality transfer. The formation
of S–S···H–N hydrogen bonds in solution
can drive conformational adaption to allow intramolecular chirality
transfer, while the formation of C=O···H–N hydrogen
bonds results in supramolecular chirality transfer to form antiparallel
helically self-assembled solid-state architectures. The dependence
on the structural information encoded in the homochiral amino acid
building blocks reveals the remarkable dynamic stereochemical space
accessible through noncovalent chirality transmission.
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Affiliation(s)
- Qi Zhang
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.,Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Stefano Crespi
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ryojun Toyoda
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Romain Costil
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Da-Hui Qu
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - He Tian
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Ben L Feringa
- Key Laboratory for Advanced Materials and Joint International Research Laboratory of Precision Chemistry and Molecular Engineering, Feringa Nobel Prize Scientist Joint Research Center, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.,Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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13
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Eijsink LE, Sardjan AS, Sinnema EG, den Besten H, van den Berg KJ, Flapper J, van Gemert R, Feringa BL, Browne WR. In situ EPR and Raman spectroscopy in the curing of bis-methacrylate-styrene resins. RSC Adv 2022; 12:2537-2548. [PMID: 35425317 PMCID: PMC8979059 DOI: 10.1039/d1ra09386j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 01/10/2022] [Indexed: 11/21/2022] Open
Abstract
The curing of bis-methacrylate-styrene resins initiated by the cobalt catalyzed decomposition of cumyl hydroperoxide is monitored at ambient temperatures in situ by EPR and Raman spectroscopy. EPR spectroscopy shows the appearance of organic radicals after ca. 1 h from initiation with an increase in intensity from both polystyrene and methacrylate based radical species over a further ca. 2 h period to reach a maximum spin concentration of ca. 2-3 mM. Alkene conversion to polymer was monitored by Raman spectroscopy in real time in situ with EPR spectroscopy and reveals that the appearance of the radical signals is first observed only as the conversion approaches its maximum extent (70% at room temperature), i.e., the resin reaches a glass-like state. The radicals persist for several months on standing at room temperature. Flash frozen samples (77 K) did not show EPR signals within 1 h of initiation. The nature of the radicals responsible for the EPR spectra observed were explored by DFT methods and isotope labelling experiments (D8-styrene) and correspond to radicals of both methacrylate and polystyrene. Combined temperature dependent EPR and Raman spectroscopy shows that conversion increases rapidly upon heating of a cured sample, reaching full conversion at 80 °C with initially little effect on the EPR spectrum. Over time (i.e. subsequent to reaching full conversion of alkene) there was a small but clear increase in the EPR signal due to the methacrylate based radicals and minor decrease in the signal due to the polystyrene based radicals. The appearance of the radical signals as the reaction reaches completion and their absence in samples flash frozen before polymerization has halted, indicate that the observed radicals are non-propagating. The formation of the radicals due to stress within the samples is excluded. Hence, the observed radicals are a representative of the steady state concentration of radicals present in the resin over the entire timespan of the polymerization. The data indicate that the lack of EPR signals is most likely due to experimental aspects, in particular spin saturation, rather than low steady state concentrations of propagating radicals during polymerization.
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Affiliation(s)
- Linda E Eijsink
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands
| | - Andy S Sardjan
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands
| | - Esther G Sinnema
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands
| | - Hugo den Besten
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands
| | | | - Jitte Flapper
- Akzo Nobel Decorative Coatings B.V. Rijksstraatweg 31 Sassenheim 2171 AJ The Netherlands
| | - Rogier van Gemert
- Akzo Nobel Car Refinishes N.V. Rijksstraatweg 31 Sassenheim 2171 AJ The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 Groningen 9747AG The Netherlands
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14
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Feringa R, Siebe HS, Klement WJN, Steen JD, Browne WR. Single wavelength colour tuning of spiropyran and dithienylethene based photochromic coatings. Mater Adv 2022; 3:282-289. [PMID: 35128415 PMCID: PMC8724907 DOI: 10.1039/d1ma00839k] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Accepted: 10/07/2021] [Indexed: 05/16/2023]
Abstract
Controlling the transmission of thin films with external stimuli is an important goal in functional optical materials and devices. Tuning is especially challenging where both broad band (neutral density filtering) and spectrally varied (colour) transmission are required. The external control provided by photochemically driven switching, between transmission levels and colours, is functionally simple from a device perspective. The limits due to the spectral ranges of individual photochromic compounds can be overcome by combining several photochromes within one material or device. Here we show that a combination of photochromic molecular switches immobilised in a PMMA polymer matrix enables tuning of colour and transparency. We show that only a single excitation wavelength is required through the use of the primary inner filter effect and the layered construction of the films in which the photochromes nitrospiropyran (NSP), and nitrothiospiropyran (TSP) or 1,2-bis-terthienyl-hexafluorocyclopentene (DTE) are separated spatially. The approach taken circumvents the need to match photochemical quantum yields and thermal reactivity of the component photochromes. The photochemical switching of the films was characterised by UV/vis absorption spectroscopy and shows that switching rates and photostationary states are limited by inner filter effects rather than the intrinsic properties of photochromes, such as photochemical quantum yields and thermal stability. The photochemical behaviour and stability of the photochromes in solution and in the PMMA films were compared and the concentration range over which self-inhibition of photochemical switching occurs was established. The rate of photochemical switching and the difference in transmission between the spiropyran and merocyanine forms in solution enable prediction of the performance in the films and enable rational design of colour tuning ranges and responsivity in thin film filters.
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Affiliation(s)
- Ruben Feringa
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Harmke S Siebe
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - W J Niels Klement
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Jorn D Steen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
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15
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Stähler C, Grunenberg L, Terban MW, Browne WR, Doellerer D, Kathan M, Etter M, Lotsch BV, Feringa BL, Krause S. Light-Driven Molecular Motors Embedded in Covalent Organic Frameworks. Chem Sci 2022; 13:8253-8264. [PMID: 35919721 PMCID: PMC9297439 DOI: 10.1039/d2sc02282f] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 05/31/2022] [Indexed: 11/21/2022] Open
Abstract
The incorporation of molecular machines into the backbone of porous framework structures will facilitate nano actuation, enhanced molecular transport, and other out-of-equilibrium host-guest phenomena in well-defined 3D solid materials. In...
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Affiliation(s)
- Cosima Stähler
- Stratingh Institute for Chemistry, Rijksuniversiteit Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Lars Grunenberg
- Max Planck Institute for Solid State Research Heisenbergstr. 1 70569 Stuttgart Germany
- Department of Chemistry, Ludwig-Maximilians-Universität (LMU) Butenandtstr. 5-13 81377 Munich Germany
| | - Maxwell W Terban
- Max Planck Institute for Solid State Research Heisenbergstr. 1 70569 Stuttgart Germany
| | - Wesley R Browne
- Stratingh Institute for Chemistry, Rijksuniversiteit Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Daniel Doellerer
- Stratingh Institute for Chemistry, Rijksuniversiteit Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Michael Kathan
- Stratingh Institute for Chemistry, Rijksuniversiteit Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Martin Etter
- Deutsches Elektronen-Synchrotron (DESY) Notkestr. 85 22607 Hamburg Germany
| | - Bettina V Lotsch
- Max Planck Institute for Solid State Research Heisenbergstr. 1 70569 Stuttgart Germany
- Department of Chemistry, Ludwig-Maximilians-Universität (LMU) Butenandtstr. 5-13 81377 Munich Germany
- E-conversion Lichtenbergstrasse 4a 85748 Garching Germany
| | - Ben L Feringa
- Stratingh Institute for Chemistry, Rijksuniversiteit Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Simon Krause
- Max Planck Institute for Solid State Research Heisenbergstr. 1 70569 Stuttgart Germany
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16
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Wonink MBS, Corbet BP, Kulago AA, Boursalian GB, de Bruin B, Otten E, Browne WR, Feringa BL. Three-State Switching of an Anthracene Extended Bis-thiaxanthylidene with a Highly Stable Diradical State. J Am Chem Soc 2021; 143:18020-18028. [PMID: 34695359 PMCID: PMC8569810 DOI: 10.1021/jacs.1c05938] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
A multistable molecular switching system based on an anthracene-extended bis-thiaxanthylidene with three individually addressable states that can be interconverted by electrochemical, thermal, and photochemical reactions is reported. Besides reversible switching between an open-shell diradical- and a closed-shell electronic configuration, our findings include a third dicationic state and control by multiple actuators. This dicationic state with an orthogonal conformation can be switched electrochemically with the neutral open-shell triplet state with orthogonal conformation, which was characterized by EPR. The remarkably stable diradical shows kinetic stability as a result of a significant activation barrier for isomerization to a more stable neutral closed-shell folded geometry. We ascribe this activation barrier of ΔG⧧(293 K) = 25.7 kcal mol-1 to steric hindrance in the fjord region of the overcrowded alkene structure. The folded closed-shell state can be converted back to the diradical state by irradiation with 385 nm. The folded state can also be oxidized to the dicationic state. These types of molecules with multiple switchable states and in particular stable diradicals show great potential in the design of new functional materials such as memory devices, logic gates, and OFETs.
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Affiliation(s)
- Marco B S Wonink
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Brian P Corbet
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Artem A Kulago
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Gregory B Boursalian
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Bas de Bruin
- Van't Hoff Institute for Molecular Sciences (HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Edwin Otten
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry and Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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17
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Genuino H, Meinds TG, Broekman JOP, Staal M, Brinksma J, Wielema T, Picchioni F, Browne WR, Deuss PJ, Heeres HJ. Iron Tetrasulfonatophthalocyanine-Catalyzed Starch Oxidation Using H 2O 2: Interplay between Catalyst Activity, Selectivity, and Stability. ACS Omega 2021; 6:13847-13857. [PMID: 34095677 PMCID: PMC8173618 DOI: 10.1021/acsomega.1c01407] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 05/06/2021] [Indexed: 06/12/2023]
Abstract
Oxidized starch can be efficiently prepared using H2O2 as an oxidant and iron(III) tetrasulfophthalocyanine (FePcS) as a catalyst, with properties in the same range as those for commercial oxidized starches prepared using NaOCl. Herein, we performed an in-depth study on the oxidation of potato starch focusing on the mode of operation of this green catalytic system and its fate as the reaction progresses. At optimum batch reaction conditions (H2O2/FePcS molar ratio of 6000, 50 °C, and pH 10), a high product yield (91 wt %) was obtained with substantial degrees of substitution (DSCOOH of 1.4 and DSCO of 4.1 per 100 AGU) and significantly reduced viscosity (197 mPa·s) by dosing H2O2. Model compound studies showed limited activity of the catalyst for C6 oxidation, indicating that carboxylic acid incorporation likely results from C-C bond cleavage events. The influence of the process conditions on the stability of the FePcS catalyst was studied using UV-vis and Raman spectroscopic techniques, revealing that both increased H2O2 concentration and temperature promote the irreversible degradation of the FePcS catalyst at high pH. The rate and extent of FePcS degradation were found to strongly depend on the initial H2O2 concentration where also the rapid decomposition of H2O2 by FePcS occurs. These results explain why the slow addition of H2O2 in combination with low FePcS catalyst concentration is beneficial for the efficient application in starch oxidation.
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Affiliation(s)
- Homer
C. Genuino
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Tim G. Meinds
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - J. O. P. Broekman
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Marcel Staal
- Avebe
Innovation Center, Zernikelaan 8, 9747 AW Groningen, The Netherlands
| | - Jelle Brinksma
- Avebe
Innovation Center, Zernikelaan 8, 9747 AW Groningen, The Netherlands
| | - Thomas Wielema
- Avebe
Innovation Center, Zernikelaan 8, 9747 AW Groningen, The Netherlands
| | - Francesco Picchioni
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R. Browne
- Stratingh
Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Peter J. Deuss
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Hero J. Heeres
- Department
of Chemical Engineering (ENTEG), University
of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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18
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Abstract
![]()
The bistability of
molecular switches is an essential characteristic
in their use as functional components in molecular-based devices and
machines. For photoswitches, light-driven switching between two stable
states proceeds via short-lived changes of the bond order in electronically
excited states. Here, bistable switching of a ditertbutyl-substituted
spiropyran photoswitch is instead demonstrated by oxidation and subsequent
reduction in an overall four-state cycle. The spiropyran structure
chosen has reduced sensitivity to the effect of secondary electrochemical
processes such as H+ production and provides transient
access to a decreased thermal Z–E isomerization barrier in the one electron oxidized state, akin to
that achieved in the corresponding photochemical path. Thus, we show
that the energy needed for switching spiropyrans to the merocyanine
form on demand, typically delivered by a photon, can instead be provided
electrochemically. This opens up further opportunities for the utilization
of spiropyrans in electrically controlled applications and devices.
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Affiliation(s)
- Jorn D Steen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Daniël R Duijnstee
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Andy S Sardjan
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Jacopo Martinelli
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Luuk Kortekaas
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Denis Jacquemin
- Université de Nantes, CEISAM UMR 6230, CNRS, F-44000 Nantes, France
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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19
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Roy P, Sardjan AS, Cnossen A, Browne WR, Feringa BL, Meech SR. Excited State Structure Correlates with Efficient Photoconversion in Unidirectional Motors. J Phys Chem Lett 2021; 12:3367-3372. [PMID: 33784091 DOI: 10.1021/acs.jpclett.1c00710] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The design of unidirectional photomolecular motors demands a critical understanding of an ultrafast photochemical isomerization. An intermediate dark excited state mediates the reaction via a conical intersection (CI) with the ground state, but a correlation between molecular structure and photoisomerization efficiency has remained elusive. Here femtosecond stimulated Raman spectroscopy captures vibrational spectra of the dark state in a set of molecular motors bearing different substituents. A direct correlation between isomerization quantum yield, dark state lifetime, and excited state vibrational spectrum is found. Electron withdrawing substituents lead to activity in lower frequency modes, which we correlate with a pyramidalization distortion at the ethylenic axle occurring within 100 fs. This structure is not formed with an electron donating substituent, where the axle retains double bond character. Further structural reorganization is observed and assigned to excited state reorganization and charge redistribution on the sub-picosecond time scale. The correlation of the dark state structure with photoconversion performance suggests guidelines for developing new more efficient motor derivatives.
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Affiliation(s)
- Palas Roy
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Andy S Sardjan
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Arjen Cnossen
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
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20
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Roy P, Sardjan AS, Danowski W, Browne WR, Feringa BL, Meech SR. Photophysics of First-Generation Photomolecular Motors: Resolving Roles of Temperature, Friction, and Medium Polarity. J Phys Chem A 2021; 125:1711-1719. [PMID: 33606528 DOI: 10.1021/acs.jpca.0c11050] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Light-driven unidirectional molecular rotary motors have the potential to power molecular machines. Consequently, optimizing their speed and efficiency is an important objective. Here, we investigate factors controlling the photochemical yield of the prototypical unidirectional rotary motor, a sterically overcrowded alkene, through detailed investigation of its excited-state dynamics. An isoviscosity analysis of the ultrafast fluorescence decay data resolves friction from barrier effects and reveals a 3.4 ± 0.5 kJ mol-1 barrier to excited-state decay in nonpolar media. Extension of this analysis to polar solvents shows that this barrier height is a strong function of medium polarity and that the decay pathway becomes near barrierless in more polar media. Thus, the properties of the medium can be used as a route for controlling the motor's excited-state dynamics. The connection between these dynamics and the quantum yield of photochemical isomerization is probed. The photochemical quantum yield is shown to be a much weaker function of solvent polarity, and the most efficient excited-state decay pathway does not lead to a strongly enhanced quantum yield for isomerization. These results are discussed in terms of the solvent dependence of the complex multidimensional excited-state reaction coordinate.
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Affiliation(s)
- Palas Roy
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
| | - Andy S Sardjan
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Wojciech Danowski
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Ben L Feringa
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Stephen R Meech
- School of Chemistry, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, U.K
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21
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Siebe HS, Chen Q, Li X, Xu Y, Browne WR, Bell SEJ. Filter paper based SERS substrate for the direct detection of analytes in complex matrices. Analyst 2021; 146:1281-1288. [PMID: 33426548 DOI: 10.1039/d0an02103b] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Surface-enhanced Raman spectroscopy (SERS) is an emerging analytical technique for chemical analysis, which is favourable due to its combination of short measurement time, high sensitivity and molecular specificity. However, the application of SERS is still limited, largely because in real samples the analyte is often present in a complex matrix that contains micro/macro particles that block the probe laser, as well as molecular contaminants that compete for the enhancing surface. Here, we show a simple and scalable spray-deposition technique to fabricate SERS-active paper substrates which combine sample filtration and enhancement in a single material. Unlike previous spray-deposition methods, in which simple colloidal nanoparticles were sprayed onto solid surfaces, here the colloidal nanoparticles are mixed with hydroxyethyl cellulose (HEC) polymer before application. This leads to significantly improved uniformity in the distribution of enhancing particles as the film dries on the substrate surface. Importantly, the polymer matrix also protects the enhancing particles from air-oxidation during storage but releases them to provide SERS enhancement when the film is rehydrated. These SERS-paper substrates are highly active and a model analyte, crystal violet, was detected down to 4 ng in 10 μL of sample with less than 20% point-by-point signal deviation. The filter paper and HEC effectively filter out both interfering micro/macro particles and molecular (protein) contaminants, allowing the SERS-paper substrates to be used for SERS detection of thiram in mud and melamine in the presence of protein down to nanogram levels without sample pre-treatment or purification.
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Affiliation(s)
- Harmke S Siebe
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
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22
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Kortekaas L, Browne WR. Correction: The evolution of spiropyran: fundamentals and progress of an extraordinarily versatile photochrome. Chem Soc Rev 2021; 50:2211. [PMID: 33524091 DOI: 10.1039/d1cs90005f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Correction for 'The evolution of spiropyran: fundamentals and progress of an extraordinarily versatile photochrome' by Luuk Kortekaas et al., Chem. Soc. Rev., 2019, 48, 3406-3424, DOI: 10.1039/C9CS00203K.
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Affiliation(s)
- Luuk Kortekaas
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
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23
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Wegeberg C, Skavenborg ML, Liberato A, McPherson JN, Browne WR, Hedegård ED, McKenzie CJ. Engineering the Oxidative Potency of Non-Heme Iron(IV) Oxo Complexes in Water for C-H Oxidation by a cis Donor and Variation of the Second Coordination Sphere. Inorg Chem 2021; 60:1975-1984. [PMID: 33470794 DOI: 10.1021/acs.inorgchem.0c03441] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A series of iron(IV) oxo complexes, which differ in the donor (CH2py or CH2COO-) cis to the oxo group, three with hemilabile pendant donor/second coordination sphere base/acid arms (pyH/py or ROH), have been prepared in water at pH 2 and 7. The νFe═O values of 832 ± 2 cm-1 indicate similar FeIV═O bond strengths; however, different reactivities toward C-H substrates in water are observed. HAT occurs at rates that differ by 1 order of magnitude with nonclassical KIEs (kH/kD = 30-66) consistent with hydrogen atom tunneling. Higher KIEs correlate with faster reaction rates as well as a greater thermodynamic stability of the iron(III) resting states. A doubling in rate from pH 7 to pH 2 for substrate C-H oxidation by the most potent complex, that with a cis-carboxylate donor, [FeIVO(Htpena)]2+, is observed. Supramolecular assistance by the first and second coordination spheres in activating the substrate is proposed. The lifetime of this complex in the absence of a C-H substrate is the shortest (at pH 2, 3 h vs up to 1.3 days for the most stable complex), implying that slow water oxidation is a competing background reaction. The iron(IV)═O complex bearing an alcohol moiety in the second coordination sphere displays significantly shorter lifetimes due to a competing selective intramolecular oxidation of the ligand.
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Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.,Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Mathias L Skavenborg
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.,Water Research Centre, School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales, Australia
| | - Andrea Liberato
- Universidad de Cádiz, Facultad de Ciencias, Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Puerto Real, Cádiz 11510, Spain
| | - James N McPherson
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Erik D Hedegård
- Division of Theoretical Chemistry, Lund University, Naturvetarvägen 14, 221 00 Lund, Sweden
| | - Christine J McKenzie
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
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24
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Danowski W, van Leeuwen T, Browne WR, Feringa BL. Photoresponsive porous materials. Nanoscale Adv 2021; 3:24-40. [PMID: 36131866 PMCID: PMC9417539 DOI: 10.1039/d0na00647e] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 11/11/2020] [Indexed: 05/04/2023]
Abstract
Molecular machines, switches, and motors enable control over nanoscale molecular motion with unprecedented precision in artificial systems. Integration of these compounds into robust material scaffolds, in particular nanostructured solids, is a fabrication strategy for smart materials with unique properties that can be controlled with external stimuli. Here, we describe a subclass of these structures, namely light-responsive porous materials metal-organic frameworks (MOFs), covalent-organic frameworks (COFs), and porous aromatic frameworks (PAFs) appended with molecular photoswitches. In this review, we provide an overview of a broad range of light-responsive porous materials focusing on potential applications.
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Affiliation(s)
- Wojciech Danowski
- Synthetic Organic Chemistry, Stratingh Institute for Chemistry, University of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
| | - Thomas van Leeuwen
- Synthetic Organic Chemistry, Stratingh Institute for Chemistry, University of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
| | - Ben L Feringa
- Synthetic Organic Chemistry, Stratingh Institute for Chemistry, University of Groningen Nijenborgh 4 Groningen 9747 AG The Netherlands
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25
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Török P, Unjaroen D, Viktória Csendes F, Giorgi M, Browne WR, Kaizer J. A nonheme peroxo-diiron(III) complex exhibiting both nucleophilic and electrophilic oxidation of organic substrates. Dalton Trans 2021; 50:7181-7185. [PMID: 34019062 PMCID: PMC8168641 DOI: 10.1039/d1dt01502h] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The complex [FeIII2(μ-O2)(L3)4(S)2]4+ (L3 = 2-(4-thiazolyl)benzimidazole, S = solvent) forms upon reaction of [FeII(L3)2] with H2O2 and is a functional model of peroxo-diiron intermediates invoked during the catalytic cycle of oxidoreductases. The spectroscopic properties of the complex are in line with those of complexes formed with N-donor ligands. [FeIII2(μ-O2)(L3)4(S)2]4+ shows both nucleophilic (aldehydes) and electrophilic (phenol, N,N-dimethylanilines) oxidative reactivity and unusually also electron transfer oxidation. A bidentate ligand based iron complex shows nucleophillic and electrophillice reactivity in the oxidation of organic substrates.![]()
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Affiliation(s)
- Patrik Török
- Research Group of Bioorganic and Biocoordination Chemistry, University of Pannonia, H-8200 Veszprém, Hungary.
| | - Duenpen Unjaroen
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
| | - Flóra Viktória Csendes
- Research Group of Bioorganic and Biocoordination Chemistry, University of Pannonia, H-8200 Veszprém, Hungary.
| | - Michel Giorgi
- Aix-Marseille Université, FR1739, Spectropole, Campus St Jérome, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
| | - József Kaizer
- Research Group of Bioorganic and Biocoordination Chemistry, University of Pannonia, H-8200 Veszprém, Hungary.
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26
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Kortekaas L, Browne WR. Correction: The evolution of spiropyran: fundamentals and progress of an extraordinarily versatile photochrome. Chem Soc Rev 2020; 49:8868. [PMID: 33196730 DOI: 10.1039/d0cs90099k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Correction for 'The evolution of spiropyran: fundamentals and progress of an extraordinarily versatile photochrome' by Luuk Kortekaas et al., Chem. Soc. Rev., 2019, 48, 3406-3424, DOI: .
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Affiliation(s)
- Luuk Kortekaas
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands.
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27
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Mejías SH, Roelfes G, Browne WR. Impact of binding to the multidrug resistance regulator protein LmrR on the photo-physics and -chemistry of photosensitizers. Phys Chem Chem Phys 2020; 22:12228-12238. [PMID: 32432253 DOI: 10.1039/d0cp01755h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Light activated photosensitizers generate reactive oxygen species (ROS) that interfere with cellular components and can induce cell death, e.g., in photodynamic therapy (PDT). The effect of cellular components and especially proteins on the photochemistry and photophysics of the sensitizers is a key aspect in drug design and the correlating cellular response with the generation of specific ROS species. Here, we show the complex range of effects of binding of photosensitizer to a multidrug resistance protein, produced by bacteria, on the formers reactivity. We show that recruitment of drug like molecules by LmrR (Lactococcal multidrug resistance Regulator) modifies their photophysical properties and their capacity to induce oxidative stress especially in 1O2 generation, including rose bengal (RB), protoporphyrin IX (PpIX), bodipy, eosin Y (EY), riboflavin (RBF), and rhodamine 6G (Rh6G). The range of neutral and charged dyes with different exited redox potentials, are broadly representative of the dyes used in PDT.
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Affiliation(s)
- Sara H Mejías
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
| | - Gerard Roelfes
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
| | - Wesley R Browne
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
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28
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Neira AC, Martínez-Alanis PR, Aullón G, Flores-Alamo M, Zerón P, Company A, Chen J, Kasper JB, Browne WR, Nordlander E, Castillo I. Correction to "Oxidative Cleavage of Cellobiose by Lytic Polysaccharide Monooxygenase (LPMO)-Inspired Copper Complexes". ACS Omega 2020; 5:28403. [PMID: 33163824 PMCID: PMC7643330 DOI: 10.1021/acsomega.0c04910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Indexed: 06/11/2023]
Abstract
[This corrects the article DOI: 10.1021/acsomega.9b00785.].
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29
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Abstract
![]()
The spiropyran
family of photochromes are key components in molecular-based responsive
materials and devices, e.g., as multiphotochromes, covalently coupled
dyads, triads, etc. This attention is in no small part due to the
change in properties that accompany the switch between spiropyran
and merocyanine forms. Although the spiropyran is a single structural
isomer, the merocyanine form represents a family of isomers (TTT, TTC, CCT, etc.) and
protonation states. Combining two spiropyrans into one compound increases
the number of possible structures dramatically and the interaction
between the units determines, which are impeded due to intramolecular
quenching of excited states. Here, we show that the coupling of two
spiropyran photochromes through their phenol units yields favorable
interactions (crosstalk) between the components that provides access
to species inaccessible with the component monospiropyran alone. Specifically,
the ring opening of one spiropyran unit, which is thermally stable
at −30 °C, prevents ring opening of the second spiropyran
unit. Furthermore, whereas protonated E- and Z-monomerocyanines were previously shown to undergo thermal-
and photo-equilibration, the corresponding protonated E- and Z- bimerocyanines are thermally stable and
show one-way photoisomerization from the Z,Z- to an emissive E,E-bimerocyanine
form. Subsequent deprotonation at room temperature resets the system
to the bispiro ring-closed form, but deprotonation at −30 °C
yields the otherwise inaccessible bimerocyanine form. This form is
photochemically inert but undergoes a two-step thermal relaxation
via the merocyanine-spiropyran form, showing that the connection at
the phenol units provides sufficient intramolecular interaction to
fine-tune the complex isomerization pathways of spiropyrans and demonstrating
noncommutability in photo- and pH-regulated multistep isomerization
pathways.
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Affiliation(s)
- Luuk Kortekaas
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Jorn D Steen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Daniël R Duijnstee
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Denis Jacquemin
- Université de Nantes, CNRS, CEISAM UMR 6230, F-44000 Nantes, France
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
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30
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Danowski W, Castiglioni F, Sardjan AS, Krause S, Pfeifer L, Roke D, Comotti A, Browne WR, Feringa BL. Visible-Light-Driven Rotation of Molecular Motors in a Dual-Function Metal-Organic Framework Enabled by Energy Transfer. J Am Chem Soc 2020; 142:9048-9056. [PMID: 32324391 PMCID: PMC7232677 DOI: 10.1021/jacs.0c03063] [Citation(s) in RCA: 59] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Indexed: 11/29/2022]
Abstract
The visible-light-driven rotation of an overcrowded alkene-based molecular motor strut in a dual-function metal-organic framework (MOF) is reported. Two types of functional linkers, a palladium-porphyrin photosensitizer and a bispyridine-derived molecular motor, were used to construct the framework capable of harvesting low-energy green light to power the rotary motion. The molecular motor was introduced in the framework using the postsynthetic solvent-assisted linker exchange (SALE) method, and the structure of the material was confirmed by powder (PXRD) and single-crystal X-ray (SC-XRD) diffraction. The large decrease in the phosphorescence lifetime and intensity of the porphyrin in the MOFs upon introduction of the molecular motor pillars confirms efficient triplet-to-triplet energy transfer between the porphyrin linkers and the molecular motor. Near-infrared Raman spectroscopy revealed that the visible light-driven rotation of the molecular motor proceeds in the solid state at rates similar to those observed in solution.
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Affiliation(s)
- Wojciech Danowski
- Centre
for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Fabio Castiglioni
- Department
of Materials Science, University of Milano
Bicocca, Via R. Cozzi 55, 20125 Milan, Italy
| | - Andy S. Sardjan
- Molecular
Inorganic Chemistry Group, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Simon Krause
- Centre
for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Lukas Pfeifer
- Centre
for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Diederik Roke
- Centre
for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
| | - Angiolina Comotti
- Department
of Materials Science, University of Milano
Bicocca, Via R. Cozzi 55, 20125 Milan, Italy
| | - Wesley R. Browne
- Centre
for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
- Molecular
Inorganic Chemistry Group, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Ben L. Feringa
- Centre
for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747
AG Groningen, The Netherlands
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31
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Sardjan AS, Roy P, Danowski W, Bressan G, Nunes dos Santos Comprido L, Browne WR, Feringa BL, Meech SR. Cover Feature: Ultrafast Excited State Dynamics in a First Generation Photomolecular Motor (ChemPhysChem 7/2020). Chemphyschem 2020. [DOI: 10.1002/cphc.202000179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Andy S. Sardjan
- Molecular Inorganic Chemistry Stratingh Institute for ChemistryUniversity of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Palas Roy
- School of ChemistryUniversity of East Anglia Norwich Research Park Norwich NR4 7TJ UK
| | - Wojciech Danowski
- Synthetic Organic Chemistry Stratingh Institute for ChemistryUniversity of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Giovanni Bressan
- School of ChemistryUniversity of East Anglia Norwich Research Park Norwich NR4 7TJ UK
| | - Laura Nunes dos Santos Comprido
- Molecular Inorganic Chemistry Stratingh Institute for ChemistryUniversity of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Wesley R. Browne
- Molecular Inorganic Chemistry Stratingh Institute for ChemistryUniversity of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Ben. L. Feringa
- Synthetic Organic Chemistry Stratingh Institute for ChemistryUniversity of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Stephen R. Meech
- School of ChemistryUniversity of East Anglia Norwich Research Park Norwich NR4 7TJ UK
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32
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Sardjan AS, Roy P, Danowski W, Bressan G, Nunes Dos Santos Comprido L, Browne WR, Feringa BL, Meech SR. Ultrafast Excited State Dynamics in a First Generation Photomolecular Motor. Chemphyschem 2020; 21:594-599. [PMID: 31975490 PMCID: PMC7187380 DOI: 10.1002/cphc.201901179] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 01/17/2020] [Indexed: 12/13/2022]
Abstract
Efficient photomolecular motors will be critical elements in the design and development of molecular machines. Optimisation of the quantum yield for photoisomerisation requires a detailed understanding of molecular dynamics in the excited electronic state. Here we probe the primary photophysical processes in the archetypal first generation photomolecular motor, with sub‐50 fs time resolved fluorescence spectroscopy. A bimodal relaxation is observed with a 100 fs relaxation of the Franck‐Condon state to populate a red‐shifted state with a reduced transition moment, which then undergoes multi‐exponential decay on a picosecond timescale. Oscillations due to the excitation of vibrational coherences in the S1 state are seen to survive the ultrafast structural relaxation. The picosecond relaxation reveals a strong solvent friction effect which is thus ascribed to torsion about the C−C axle. This behaviour is contrasted with second generation photomolecular motors; the principal differences are explained by the existence of a barrier on the excited state surface in the case of the first‐generation motors which is absent in the second generation. These results will help to provide a basis for designing more efficient molecular motors in the future.
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Affiliation(s)
- Andy S Sardjan
- Molecular Inorganic Chemistry Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Palas Roy
- School of Chemistry, University of East Anglia Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Wojciech Danowski
- Synthetic Organic Chemistry Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Giovanni Bressan
- School of Chemistry, University of East Anglia Norwich Research Park, Norwich, NR4 7TJ, UK
| | - Laura Nunes Dos Santos Comprido
- Molecular Inorganic Chemistry Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Wesley R Browne
- Molecular Inorganic Chemistry Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Ben L Feringa
- Synthetic Organic Chemistry Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Stephen R Meech
- School of Chemistry, University of East Anglia Norwich Research Park, Norwich, NR4 7TJ, UK
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33
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Wang L, Gennari M, Cantú Reinhard FG, Padamati SK, Philouze C, Flot D, Demeshko S, Browne WR, Meyer F, de Visser SP, Duboc C. O2 Activation by Non-Heme Thiolate-Based Dinuclear Fe Complexes. Inorg Chem 2020; 59:3249-3259. [DOI: 10.1021/acs.inorgchem.9b03633] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Lianke Wang
- Institutes of Physical Science and Information Technology, Anhui University, 230601 Hefei, Anhui, P. R. China
- Univ. Grenoble Alpes, CNRS UMR 5250, DCM, F-38000 Grenoble, France
| | - Marcello Gennari
- Univ. Grenoble Alpes, CNRS UMR 5250, DCM, F-38000 Grenoble, France
| | - Fabián G. Cantú Reinhard
- Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Sandeep K. Padamati
- Univ. Grenoble Alpes, CNRS UMR 5250, DCM, F-38000 Grenoble, France
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | | | - David Flot
- ESRF European Synchrotron 71, Ave Martyrs Grenoble, 38000 Grenoble, France
| | - Serhiy Demeshko
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
| | - Wesley R. Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Franc Meyer
- Institute of Inorganic Chemistry, University of Göttingen, Tammannstrasse 4, D-37077 Göttingen, Germany
| | - Sam P. de Visser
- Manchester Institute of Biotechnology and Department of Chemical Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
| | - Carole Duboc
- Univ. Grenoble Alpes, CNRS UMR 5250, DCM, F-38000 Grenoble, France
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34
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Mecozzi F, Dong JJ, Angelone D, Browne WR, Eisink NNHM. Oxidative Cleavage of Alkene C=C Bonds Using a Manganese Catalyzed Oxidation with H 2O 2 Combined with Periodate Oxidation. European J Org Chem 2019; 2019:7151-7158. [PMID: 31866758 PMCID: PMC6899713 DOI: 10.1002/ejoc.201901380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Indexed: 11/24/2022]
Abstract
A one‐pot multi‐step method for the oxidative cleavage of alkenes to aldehydes/ketones under ambient conditions is described as an alternative to ozonolysis. The first step is a highly efficient manganese catalyzed epoxidation/cis‐dihydroxylation of alkenes. This step is followed by an Fe(III) assisted ring opening of the epoxide (where necessary) to a 1,2‐diol. Carbon–carbon bond cleavage is achieved by treatment of the diol with sodium periodate. The conditions used in each step are not only compatible with the subsequent step(s), but also provide for increased conversion compared to the equivalent reactions carried out on the isolated intermediate compounds. The described procedure allows for carbon–carbon bond cleavage in the presence of other alkenes, oxidation sensitive moieties and other functional groups; the mild conditions (r.t.) used in all three steps make this a viable general alternative to ozonolysis and especially for use under flow or continuous batch conditions.
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Affiliation(s)
- Francesco Mecozzi
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747 AGGroningenThe Netherlands
| | - Jia Jia Dong
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747 AGGroningenThe Netherlands
| | - Davide Angelone
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747 AGGroningenThe Netherlands
| | - Wesley R. Browne
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747 AGGroningenThe Netherlands
| | - Niek N. H. M. Eisink
- USSEFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747 AGGroningenThe Netherlands
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35
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Steen JD, Stepanovic S, Parvizian M, de Boer JW, Hage R, Chen J, Swart M, Gruden M, Browne WR. Lewis versus Brønsted Acid Activation of a Mn(IV) Catalyst for Alkene Oxidation. Inorg Chem 2019; 58:14924-14930. [PMID: 31625380 PMCID: PMC6832668 DOI: 10.1021/acs.inorgchem.9b02737] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
![]()
Lewis acid (LA) activation
by coordination to metal oxido species
has emerged as a new strategy in catalytic oxidations. Despite the
many reports of enhancement of performance in oxidation catalysis,
direct evidence for LA-catalyst interactions under catalytically relevant
conditions is lacking. Here, we show, using the oxidation of alkenes
with H2O2 and the catalyst [Mn2(μ-O)3(tmtacn)2](PF6)2 (1), that Lewis acids commonly used to enhance catalytic activity,
e.g., Sc(OTf)3, in fact undergo hydrolysis with adventitious
water to release a strong Brønsted acid. The formation of Brønsted
acids in situ is demonstrated using a combination of resonance Raman,
UV/vis absorption spectroscopy, cyclic voltammetry, isotope labeling,
and DFT calculations. The involvement of Brønsted acids in LA
enhanced systems shown here holds implications for the conclusions
reached in regard to the relevance of direct LA-metal oxido interactions
under catalytic conditions. Lewis acid activation of oxidation
catalysts is proposed
to be through binding of the Lewis acids to metal-oxo species. The
activity of the catalyst [Mn2(μ-O)3(tmtacn)2](PF6)2 in the oxidation of alkenes
with H2O2 appears to correlate with the strength
of the Lewis acid used for its activation. We show that the correlation
arises from the relative propensity of the Lewis acids to generate
Brønsted acids in situ.
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Affiliation(s)
- Jorn D Steen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands
| | - Stepan Stepanovic
- Faculty of Chemistry , University of Belgrade , Studentski trg 12-16 , 11000 Belgrade , Serbia
| | - Mahsa Parvizian
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands
| | - Johannes W de Boer
- Catexel B.V. , BioPartner Center Leiden , Galileiweg 8 , 2333 BD Leiden , The Netherlands
| | - Ronald Hage
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands.,Catexel B.V. , BioPartner Center Leiden , Galileiweg 8 , 2333 BD Leiden , The Netherlands
| | - Juan Chen
- Department of Applied Chemistry, School of Science , Northwestern Polytechnical University , Xi'an , Shaanxi 710072 , China
| | - Marcel Swart
- IQCC & Departament de Química , Universitat de Girona , Campus Montilivi (Ciències) , 17003 Girona , Spain.,ICREA , Pg. Lluís Companys 23 , 08010 Barcelona , Spain
| | - Maja Gruden
- Faculty of Chemistry , University of Belgrade , Studentski trg 12-16 , 11000 Belgrade , Serbia
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , 9747 AG , Groningen , The Netherlands
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36
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Barbieri A, Kasper JB, Mecozzi F, Lanzalunga O, Browne WR. Origins of Catalyst Inhibition in the Manganese-Catalysed Oxidation of Lignin Model Compounds with H 2 O 2. ChemSusChem 2019; 12:3126-3133. [PMID: 31001914 PMCID: PMC6617720 DOI: 10.1002/cssc.201900689] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 04/13/2019] [Indexed: 05/26/2023]
Abstract
The upgrading of complex bio-renewable feedstock, such as lignocellulose, through depolymerisation benefits from the selective reactions at key functional groups. Applying homogeneous catalysts developed for selective organic oxidative transformations to complex feedstock such as lignin is challenged by the presence of interfering components. The selection of appropriate model compounds is essential in applying new catalytic systems and identifying such interferences. Here, it was shown by using as an example the oxidation of a model substrate containing a β-O-4 linkage with H2 O2 and an in situ-prepared manganese-based catalyst, capable of efficient oxidation of benzylic alcohols, that interference from compounds liberated during the reaction can prevent its application to lignocellulose depolymerisation.
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Affiliation(s)
- Alessia Barbieri
- Dipartimento di ChimicaUniversita'di Roma “La Sapienza”P.le A. Moro 5I-00185RomeItaly
| | - Johann B. Kasper
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Francesco Mecozzi
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
| | - Osvaldo Lanzalunga
- Dipartimento di ChimicaUniversita'di Roma “La Sapienza”P.le A. Moro 5I-00185RomeItaly
| | - Wesley R. Browne
- Molecular Inorganic ChemistryStratingh Institute for ChemistryFaculty of Science and EngineeringUniversity of GroningenNijenborgh 49747AGGroningenThe Netherlands
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37
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Neira A, Martínez-Alanis PR, Aullón G, Flores-Alamo M, Zerón P, Company A, Chen J, Kasper JB, Browne WR, Nordlander E, Castillo I. Oxidative Cleavage of Cellobiose by Lytic Polysaccharide Monooxygenase (LPMO)-Inspired Copper Complexes. ACS Omega 2019; 4:10729-10740. [PMID: 31460171 PMCID: PMC6648734 DOI: 10.1021/acsomega.9b00785] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 06/06/2019] [Indexed: 06/10/2023]
Abstract
The potentially tridentate ligand bis[(1-methyl-2-benzimidazolyl)ethyl]amine (2BB) was employed to prepare copper complexes [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 as bioinspired models of lytic polysaccharide copper-dependent monooxygenase (LPMO) enzymes. Solid-state characterization of [(2BB)CuI]OTf revealed a Cu(I) center with a T-shaped coordination environment and metric parameters in the range of those observed in reduced LPMOs. Solution characterization of [(2BB)CuII(H2O)2](OTf)2 indicates that [(2BB)CuII(H2O)2]2+ is the main species from pH 4 to 7.5; above pH 7.5, the hydroxo-bridged species [{(2BB)CuII(H2O) x }2(μ-OH)2]2+ is also present, on the basis of cyclic voltammetry and mass spectrometry. These observations imply that deprotonation of the central amine of Cu(II)-coordinated 2BB is precluded, and by extension, amine deprotonation in the histidine brace of LPMOs appears unlikely at neutral pH. The complexes [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 act as precursors for the oxidative degradation of cellobiose as a cellulose model substrate. Spectroscopic and reactivity studies indicate that a dicopper(II) side-on peroxide complex generated from [(2BB)CuI]OTf/O2 or [(2BB)CuII(H2O)2](OTf)2/H2O2/NEt3 oxidizes cellobiose both in acetonitrile and aqueous phosphate buffer solutions, as evidenced from product analysis by high-performance liquid chromatography-mass spectrometry. The mixture of [(2BB)CuII(H2O)2](OTf)2/H2O2/NEt3 results in more extensive cellobiose degradation. Likewise, the use of both [(2BB)CuI]OTf and [(2BB)CuII(H2O)2](OTf)2 with KO2 afforded cellobiose oxidation products. In all cases, a common Cu(II) complex formulated as [(2BB)CuII(OH)(H2O)]+ was detected by mass spectrometry as the final form of the complex.
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Affiliation(s)
- Andrea.
C. Neira
- Instituto
de Química and Facultad de Química, División
de Estudios de Posgrado, Universidad Nacional
Autónoma de México, Circuito Exterior, CU, 04510 Ciudad de
México, México
| | - Paulina R. Martínez-Alanis
- Departament
de Química Inorgànica i Orgànica and Institut
de Química Teòrica i Computacional, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Gabriel Aullón
- Departament
de Química Inorgànica i Orgànica and Institut
de Química Teòrica i Computacional, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain
| | - Marcos Flores-Alamo
- Instituto
de Química and Facultad de Química, División
de Estudios de Posgrado, Universidad Nacional
Autónoma de México, Circuito Exterior, CU, 04510 Ciudad de
México, México
| | - Paulino Zerón
- Instituto
de Química and Facultad de Química, División
de Estudios de Posgrado, Universidad Nacional
Autónoma de México, Circuito Exterior, CU, 04510 Ciudad de
México, México
| | - Anna Company
- Institut
de Química Computacional i Catàlisi (IQCC), Departament
de Química, Universitat de Girona, C/ M. Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Juan Chen
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Health, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Johann B. Kasper
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Health, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Wesley R. Browne
- Molecular
Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of
Science and Health, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands
| | - Ebbe Nordlander
- Chemical
Physics, Department of Chemistry, Lund University, Box 124, SE-221 00 Lund, Sweden
| | - Ivan Castillo
- Instituto
de Química and Facultad de Química, División
de Estudios de Posgrado, Universidad Nacional
Autónoma de México, Circuito Exterior, CU, 04510 Ciudad de
México, México
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38
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Wegeberg C, Browne WR, McKenzie CJ. cis Donor Influence on O–O Bond Lability in Iron(III) Hydroperoxo Complexes: Oxidation Catalysis and Ligand Transformation. Inorg Chem 2019; 58:8983-8994. [DOI: 10.1021/acs.inorgchem.9b00247] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R. Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Christine J. McKenzie
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
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39
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Schepke U, Gresnigt MMM, Browne WR, Abdolahzadeh S, Nijkamp J, Cune MS. Phase transformation and fracture load of stock and CAD/CAM‐customized zirconia abutments after 1 year of clinical function. Clin Oral Implants Res 2019; 30:559-569. [DOI: 10.1111/clr.13442] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Revised: 03/17/2019] [Accepted: 03/29/2019] [Indexed: 12/21/2022]
Affiliation(s)
- Ulf Schepke
- Department of Fixed and Removable Prosthodontics and Biomaterials, Center for Dentistry and Oral Hygiene University Medical Center Groningen, University of Groningen Groningen The Netherlands
| | - Marco M. M. Gresnigt
- Department of Fixed and Removable Prosthodontics and Biomaterials, Center for Dentistry and Oral Hygiene University Medical Center Groningen, University of Groningen Groningen The Netherlands
| | - Wesley R. Browne
- Faculty of Mathematics and Natural Sciences, Molecular Inorganic Chemistry, Stratingh Institute for Chemistry University of Groningen Groningen The Netherlands
| | - Shaghayegh Abdolahzadeh
- Faculty of Mathematics and Natural Sciences, Molecular Inorganic Chemistry, Stratingh Institute for Chemistry University of Groningen Groningen The Netherlands
| | - Joey Nijkamp
- Department of Fixed and Removable Prosthodontics and Biomaterials, Center for Dentistry and Oral Hygiene University Medical Center Groningen, University of Groningen Groningen The Netherlands
| | - Marco S. Cune
- Department of Fixed and Removable Prosthodontics and Biomaterials, Center for Dentistry and Oral Hygiene University Medical Center Groningen, University of Groningen Groningen The Netherlands
- Department of Oral and Maxillofacial Surgery, Prosthodontics and Special Dental Care St. Antonius Hospital Nieuwegein The Netherlands
- Department of Oral and Maxillofacial Surgery, Prosthodontics and Special Dental Care University Medical Center Utrecht Utrecht The Netherlands
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40
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Danowski W, van Leeuwen T, Abdolahzadeh S, Roke D, Browne WR, Wezenberg SJ, Feringa BL. Unidirectional rotary motion in a metal-organic framework. Nat Nanotechnol 2019; 14:488-494. [PMID: 30886378 DOI: 10.1038/s41565-019-0401-6] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 02/06/2019] [Indexed: 05/20/2023]
Abstract
Overcrowded alkene-based light-driven molecular motors are able to perform large-amplitude repetitive unidirectional rotations. Their behaviour is well understood in solution. However, Brownian motion precludes the precise positioning at the nanoscale needed to harness cooperative action. Here, we demonstrate molecular motors organized in crystalline metal-organic frameworks (MOFs). The motor unit becomes a part of the organic linker (or strut), and its spatial arrangement is elucidated through powder and single-crystal X-ray analyses and polarized optical and Raman microscopies. We confirm that the light-driven unidirectional rotation of the motor units is retained in the MOF framework and that the motors can operate in the solid state with similar rotary speed (rate of thermal helix inversion) to that in solution. These 'moto-MOFs' could in the future be used to control dynamic function in crystalline materials.
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Affiliation(s)
- Wojciech Danowski
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Thomas van Leeuwen
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Shaghayegh Abdolahzadeh
- Molecular Inorganic Chemistry Group, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Diederik Roke
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands
| | - Wesley R Browne
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
- Molecular Inorganic Chemistry Group, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
| | - Sander J Wezenberg
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
| | - Ben L Feringa
- Centre for Systems Chemistry, Stratingh Institute for Chemistry, University of Groningen, Groningen, The Netherlands.
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41
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Abstract
Spiropyrans have played a pivotal role in the emergence of the field of chromism following their discovery in the early 20th century, with almost ubiquitous use in materials applications especially since their photochromism was discovered in 1952.
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Affiliation(s)
- Luuk Kortekaas
- Molecular Inorganic Chemistry
- Stratingh institute for Chemistry
- University of Groningen
- 9747AG Groningen
- The Netherlands
| | - Wesley R. Browne
- Molecular Inorganic Chemistry
- Stratingh institute for Chemistry
- University of Groningen
- 9747AG Groningen
- The Netherlands
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42
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Wegeberg C, Fernández-Alvarez VM, de Aguirre A, Frandsen C, Browne WR, Maseras F, McKenzie CJ. Photoinduced O 2-Dependent Stepwise Oxidative Deglycination of a Nonheme Iron(III) Complex. J Am Chem Soc 2018; 140:14150-14160. [PMID: 30347152 DOI: 10.1021/jacs.8b07455] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The iron(III) complex [Fe(tpena)]2+ (tpena = N, N, N'-tris(2-pyridylmethyl)ethylendiamine- N'-acetate) undergoes irreversible O2-dependent N-demethylcarboxylation to afford [FeII(SBPy3)(MeCN)]2+ (SBPy3 = N, N-bis(2-pyridylmethyl)amine- N-ethyl-2-pyridine-2-aldimine), when irradiated with near-UV light. The loss of a mass equivalent to the glycyl group in a process involving consecutive C-C and C-N cleavages is documented by the measurement of the sequential production of CO2 and formaldehyde, respectively. Time-resolved UV-vis absorption, Mössbauer, EPR, and Raman spectroscopy have allowed the spectroscopic characterization of two iron-based intermediates along the pathway. The first of these, proposed to be a low-spin iron(II)-radical ligand complex, reacts with O2 in the rate-determining step to produce a putative alkylperoxide complex. DFT calculations suggest that this evolves into an Fe(IV)-oxo species, which can abstract a hydrogen atom from a cis methylene group of the ligand to give the second spectroscopically identified intermediate, a high-spin iron(III)-hydroxide of the product oxidized ligand, [FeIII(OH)(SBPy3)]2+. Reduction and exchange of the cohydroxo/water ligand produces the crystallographically characterized products [FeII(SBPy3)(X)]2+/3+, X = MeCN, [Zn(tpena)]+.
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Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55 , DK-5230 Odense M, Denmark.,Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , AG Groningen 9747 , The Netherlands
| | - Víctor M Fernández-Alvarez
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avgda. Països Catalans, 16 , 43007 Tarragona , Catalonia , Spain
| | - Adiran de Aguirre
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avgda. Països Catalans, 16 , 43007 Tarragona , Catalonia , Spain
| | - Cathrine Frandsen
- Department of Physics , Technical University of Denmark , DK-2800 Kongens Lyngby , Denmark
| | - Wesley R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering , University of Groningen , Nijenborgh 4 , AG Groningen 9747 , The Netherlands
| | - Feliu Maseras
- Institute of Chemical Research of Catalonia (ICIQ) , The Barcelona Institute of Science and Technology , Avgda. Països Catalans, 16 , 43007 Tarragona , Catalonia , Spain.,Departament de Química , Universitat Autònoma de Barcelona , 08193 Bellaterra , Catalonia , Spain
| | - Christine J McKenzie
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , Campusvej 55 , DK-5230 Odense M, Denmark
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43
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Chen J, Draksharapu A, Angelone D, Unjaroen D, Padamati SK, Hage R, Swart M, Duboc C, Browne WR. H 2O 2 Oxidation by Fe III-OOH Intermediates and Its Effect on Catalytic Efficiency. ACS Catal 2018; 8:9665-9674. [PMID: 30319886 PMCID: PMC6179451 DOI: 10.1021/acscatal.8b02326] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Revised: 08/30/2018] [Indexed: 11/28/2022]
Abstract
![]()
The
oxidation of the C–H and C=C bonds of hydrocarbons with
H2O2 catalyzed by non-heme iron complexes with
pentadentate ligands is widely accepted as involving a reactive FeIV=O species such as [(N4Py)FeIV=O]2+ formed by homolytic cleavage of the O–O bond of an
FeIII–OOH intermediate (where N4Py is 1,1-bis(pyridin-2-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine).
We show here that at low H2O2 concentrations
the FeIV=O species formed is detectable in methanol.
Furthermore, we show that the decomposition of H2O2 to water and O2 is an important competing pathway
that limits efficiency in the terminal oxidant and indeed dominates
reactivity except where only sub-/near-stoichiometric amounts of H2O2 are present. Although independently prepared
[(N4Py)FeIV=O]2+ oxidizes stoichiometric
H2O2 rapidly, the rate of formation of FeIV=O from the FeIII–OOH intermediate
is too low to account for the rate of H2O2 decomposition
observed under catalytic conditions. Indeed, with excess H2O2, disproportionation to O2 and H2O is due to reaction with the FeIII–OOH intermediate
and thereby prevents formation of the FeIV=O species.
These data rationalize that the activity of these catalysts with respect
to hydrocarbon/alkene oxidation is maximized by maintaining sub-/near-stoichiometric
steady-state concentrations of H2O2, which ensure
that the rate of the H2O2 oxidation by the FeIII–OOH intermediate is less than the rate of the O–O
bond homolysis and the subsequent reaction of the FeIV=O
species with a substrate.
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Affiliation(s)
- Juan Chen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Apparao Draksharapu
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Davide Angelone
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E17003 Girona, Catalonia, Spain
| | - Duenpen Unjaroen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Sandeep K. Padamati
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
| | - Ronald Hage
- Catexel BV, BioPartner Center, Galileiweg 8, 2333BD Leiden, The Netherlands
| | - Marcel Swart
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus Montilivi, E17003 Girona, Catalonia, Spain
- ICREA, Pg. Lluís Companys 23, 08010 Barcelona, Spain
| | - Carole Duboc
- Departement de Chimie Moleculaire, Univ. Grenoble Alpes/CNRS, UMR-5250, BP-53, 38041 Grenoble Cedex 9, France
| | - Wesley R. Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Science and Engineering, University of Groningen, Nijenborgh 4, 9747AG, Groningen, The Netherlands
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44
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Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Wesley R. Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Christine J. McKenzie
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark
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45
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Huijser A, Pan Q, van Duinen D, Laursen MG, El Nahhas A, Chabera P, Freitag L, González L, Kong Q, Zhang X, Haldrup K, Browne WR, Smolentsev G, Uhlig J. Shedding Light on the Nature of Photoinduced States Formed in a Hydrogen-Generating Supramolecular RuPt Photocatalyst by Ultrafast Spectroscopy. J Phys Chem A 2018; 122:6396-6406. [PMID: 30052048 DOI: 10.1021/acs.jpca.8b00916] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Photoinduced electronic and structural changes of a hydrogen-generating supramolecular RuPt photocatalyst are studied by a combination of time-resolved photoluminescence, optical transient absorption, and X-ray absorption spectroscopy. This work uses the element specificity of X-ray techniques to focus on the interplay between the photophysical and -chemical processes and the associated time scales at the catalytic Pt moiety. We observe very fast (<30 ps) photoreduction of the Pt catalytic site, followed by an ∼600 ps step into a strongly oxidized Pt center. The latter process is likely induced by oxidative addition of reactive iodine species. The oxidized Pt species is long-lived and fully recovers to the original ground state complex on a >10 μs time scale. However, the photosensitizing Ru moiety is fully restored on a much shorter ∼300 ns time scale. This reaction scheme implies that we may withdraw two electrons from a catalyst that is activated by a single photon.
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Affiliation(s)
- Annemarie Huijser
- Optical Sciences and PhotoCatalytic Synthesis Groups, MESA+ Institute , University of Twente , P.O. Box 217, 7500 AE Enschede , The Netherlands
| | - Qing Pan
- Optical Sciences and PhotoCatalytic Synthesis Groups, MESA+ Institute , University of Twente , P.O. Box 217, 7500 AE Enschede , The Netherlands
| | - David van Duinen
- Optical Sciences and PhotoCatalytic Synthesis Groups, MESA+ Institute , University of Twente , P.O. Box 217, 7500 AE Enschede , The Netherlands
| | - Mads G Laursen
- Department of Physics , Technical University of Denmark , 2800 Kongens Lyngby , Denmark
| | - Amal El Nahhas
- Department of Chemical Physics , Lund University , Getingevägen 60 , Lund 22100 , Sweden
| | - Pavel Chabera
- Department of Chemical Physics , Lund University , Getingevägen 60 , Lund 22100 , Sweden
| | - Leon Freitag
- Institute of Theoretical Chemistry, Faculty of Chemistry , University of Vienna , Währinger Str. 17 , 1090 Vienna , Austria
| | - Leticia González
- Institute of Theoretical Chemistry, Faculty of Chemistry , University of Vienna , Währinger Str. 17 , 1090 Vienna , Austria
| | - Qingyu Kong
- X-ray Sciences Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Xiaoyi Zhang
- X-ray Sciences Division , Argonne National Laboratory , Argonne , Illinois 60439 , United States
| | - Kristoffer Haldrup
- Department of Physics , Technical University of Denmark , 2800 Kongens Lyngby , Denmark
| | - Wesley R Browne
- Molecular Inorganic Chemistry Group, Stratingh Institute for Chemistry , University of Groningen , 9747 AG Groningen , The Netherlands
| | - Grigory Smolentsev
- Paul Scherrer Institute , Villigen 5232 , Switzerland.,Smart Materials International Research Center , Southern Federal University of Russia , Rostov-on-Don 344090 , Russian Federation
| | - Jens Uhlig
- Department of Chemical Physics , Lund University , Getingevägen 60 , Lund 22100 , Sweden
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46
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Abstract
Soluble model compounds, such as flavones, are frequently employed in initial and mechanistic studies under homogeneous conditions in the search for effective bleaching catalysts for raw cotton. The relevance of model substrates, such as morin and chrysin, and especially their reactivity with manganese catalysts [i.e. in combination with 1,4,7‐triazacyclononane (tacn) based ligands] applied in raw cotton bleaching with H2O2 in alkaline solutions is examined. We show that morin, used frequently as a model, is highly sensitive to oxidation with O2, by processes catalyzed by trace metal ions, that can be accelerated photochemically, although not involve generation of 1O2. The structurally related chrysin is not susceptible to such photo‐accelerated oxidation with O2. Furthermore, chrysin is oxidized by H2O2 only in the presence of a Mn‐tacn based catalyst, and does not undergo oxidation with O2 as terminal oxidant. Chrysin mimics the behavior of raw cotton's chromophores in their catalyzed oxidation with H2O2, and is likely a mechanistically relevant model compound for the study of transition metal catalysts for dye bleaching catalysts under homogeneous conditions.
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Affiliation(s)
- Shaghayegh Abdolahzadeh
- Stratingh Institute for Chemistry Faculty of Science and Engineering University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Nicola M Boyle
- Stratingh Institute for Chemistry Faculty of Science and Engineering University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
| | - Ronald Hage
- BioPartner Center Leiden Catexel Ltd Galileiweg 8 2333 BD Leiden The Netherlands
| | - Johannes W de Boer
- BioPartner Center Leiden Catexel Ltd Galileiweg 8 2333 BD Leiden The Netherlands
| | - Wesley R Browne
- Stratingh Institute for Chemistry Faculty of Science and Engineering University of Groningen Nijenborgh 4 9747AG Groningen The Netherlands
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Abstract
Spiropyrans undergo Cspiro-O bond breaking to their ring-open protonated E-merocyanine form upon protonation and irradiation via an intermediate protonated Z-merocyanine isomer. We show that the extent of acid-induced ring opening is controlled by matching both the concentration and strength of the acid used and with strong acids full ring opening to the Z-merocyanine isomer occurs spontaneously allowing its characterization by 1H NMR spectroscopy as well as UV/vis spectroscopy, and reversible switching between Z/ E-isomerization by irradiation with UV and visible light. Under sufficiently acidic conditions, both E- and Z-isomers are thermally stable. Judicious choice of acid such that its p Ka lies between that of the E- and Z-merocyanine forms enables thermally stable switching between spiropyran and E-merocyanine forms and hence pH gating between thermally irreversible and reversible photochromic switching.
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Affiliation(s)
- L Kortekaas
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences , University of Groningen , Nijenborgh 4 , 9747AG Groningen , The Netherlands
| | - J Chen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences , University of Groningen , Nijenborgh 4 , 9747AG Groningen , The Netherlands
| | - D Jacquemin
- Chimie Et Interdisciplinarité, Synthèse, Analyse, Modélisation (CEISAM) , UMR CNRS no. 6230, Université de Nantes , BP 92208, 2, Rue de la Houssinière , 44322 Nantes Cedex 3, France
| | - W R Browne
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, Faculty of Mathematics and Natural Sciences , University of Groningen , Nijenborgh 4 , 9747AG Groningen , The Netherlands
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Hall CR, Browne WR, Feringa BL, Meech SR. Mapping the Excited‐State Potential Energy Surface of a Photomolecular Motor. Angew Chem Int Ed Engl 2018; 57:6203-6207. [DOI: 10.1002/anie.201802126] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Indexed: 01/05/2023]
Affiliation(s)
| | - Wesley R. Browne
- Molecular Inorganic Chemistry Stratingh Institute for Chemistry University of Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Ben L. Feringa
- Synthetic Organic Chemistry Stratingh Institute for Chemistry University of Groningen Nijenborgh 4 9747 AG Groningen Netherlands
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Affiliation(s)
| | - Wesley R. Browne
- Molecular Inorganic Chemistry Stratingh Institute for Chemistry University of Groningen Nijenborgh 4 9747 AG Groningen Netherlands
| | - Ben L. Feringa
- Synthetic Organic Chemistry Stratingh Institute for Chemistry University of Groningen Nijenborgh 4 9747 AG Groningen Netherlands
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50
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Wegeberg C, Lauritsen FR, Frandsen C, Mørup S, Browne WR, McKenzie CJ. Cover Feature: Directing a Non-Heme Iron(III)-Hydroperoxide Species on a Trifurcated Reactivity Pathway (Chem. Eur. J. 20/2018). Chemistry 2018. [DOI: 10.1002/chem.201800709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Christina Wegeberg
- Department of Physics, Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
| | - Frants R. Lauritsen
- Department of Physics, Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
| | - Cathrine Frandsen
- Department of Physics; Technical University of Denmark; 2800 Kongens Lyngby Denmark
| | - Steen Mørup
- Department of Physics; Technical University of Denmark; 2800 Kongens Lyngby Denmark
| | - Wesley R. Browne
- Molecular Inorganic Chemistry; Stratingh Institute for Chemistry; University of Groningen; Nijenborgh 4 9747 AG Groningen The Netherlands
| | - Christine J. McKenzie
- Department of Physics, Chemistry and Pharmacy; University of Southern Denmark; Campusvej 55 5230 Odense M Denmark
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