1
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Patrick SC, Beer PD, Davis JJ. Solvent effects in anion recognition. Nat Rev Chem 2024; 8:256-276. [PMID: 38448686 DOI: 10.1038/s41570-024-00584-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/25/2024] [Indexed: 03/08/2024]
Abstract
Anion recognition is pertinent to a range of environmental, medicinal and industrial applications. Recent progress in the field has relied on advances in synthetic host design to afford a broad range of potent recognition motifs and novel supramolecular structures capable of effective binding both in solution and at derived molecular films. However, performance in aqueous media remains a critical challenge. Understanding the effects of bulk and local solvent on anion recognition by host scaffolds is imperative if effective and selective detection in real-world media is to be viable. This Review seeks to provide a framework within which these effects can be considered both experimentally and theoretically. We highlight proposed models for solvation effects on anion binding and discuss approaches to retain strong anion binding in highly competitive (polar) solvents. The synthetic design principles for exploiting the aforementioned solvent effects are explored.
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Affiliation(s)
| | - Paul D Beer
- Department of Chemistry, University of Oxford, Oxford, UK
| | - Jason J Davis
- Department of Chemistry, University of Oxford, Oxford, UK.
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2
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Bhattacharjee N, Gao X, Nathani A, Dobscha JR, Pink M, Ito T, Flood AH. Solvent Acts as the Referee in a Match-Up Between Charged and Preorganized Receptors. Chemistry 2023; 29:e202302339. [PMID: 37615829 DOI: 10.1002/chem.202302339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 08/21/2023] [Accepted: 08/22/2023] [Indexed: 08/25/2023]
Abstract
The prevalence of anion-cation contacts in biomolecular recognition under aqueous conditions suggests that ionic interactions should dominate the binding of anions in solvents across both high and low polarities. Investigations of this idea using titrations in low polarity solvents are impaired by interferences from ion pairing that prevent a clear picture of binding. To address this limitation and test the impact of ion-ion interactions across multiple solvents, we quantified chloride binding to a cationic receptor after accounting for ion pairing. In these studies, we created a chelate receptor using aryl-triazole CH donors and a quinolinium unit that directs its cationic methyl inside the binding pocket. In low-polarity dichloromethane, the 1 : 1 complex (log K1 : 1 ~ 7.3) is more stable than neutral chelates, but fortuitously comparable to a preorganized macrocycle (log K1 : 1 ~ 6.9). Polar acetonitrile and DMSO diminish stabilities of the charged receptor (log K1 : 1 ~ 3.7 and 1.9) but surprisingly 100-fold more than the macrocycle. While both receptors lose stability by dielectric screening of electrostatic stability, the cationic receptor also pays additional costs of organization. Thus even though the charged receptor has stronger binding in apolar solvents, the uncharged receptor has more anion affinity in polar solvents.
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Affiliation(s)
- Nabarupa Bhattacharjee
- Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Xinfeng Gao
- Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Akash Nathani
- Department of Chemistry, Kansas State University, 213 CBC Building, 1212 Mid-campus Dr North, Manhattan, KS 66506, USA
| | - James R Dobscha
- Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Maren Pink
- Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
| | - Takashi Ito
- Department of Chemistry, Kansas State University, 213 CBC Building, 1212 Mid-campus Dr North, Manhattan, KS 66506, USA
| | - Amar H Flood
- Department of Chemistry, Indiana University Bloomington, 800 E. Kirkwood Ave., Bloomington, IN, 47405, USA
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3
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Yao Y, Ge X, Yin Y, Minjarez R, Tong T. Antiscalants for mitigating silica scaling in membrane desalination: Effects of molecular structure and membrane process. WATER RESEARCH 2023; 246:120701. [PMID: 37837901 DOI: 10.1016/j.watres.2023.120701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/20/2023] [Accepted: 10/04/2023] [Indexed: 10/16/2023]
Abstract
Silica scaling is a major type of mineral scaling that significantly constrains the performance and efficiency of membrane desalination. While antiscalants have been commonly used to control mineral scaling formed via crystallization, there is a lack of antiscalants for silica scaling due to its unique formation mechanism of polymerization. In this study, we performed a systematic study that investigated and compared antiscalants with different functional groups and molecular weights for mitigating silica scaling in membrane distillation (MD) and reverse osmosis (RO). The efficiencies of these antiscalants were tested in both static experiments (for hindering silicic acid polymerization) as well as crossflow, dynamic MD and RO experiments (for reducing water flux decline). Our results show that antiscalants enriched with strong H-accepters and H-donors were both able to hinder silicic acid polymerization efficiently in static experiments, with their antiscaling performance being a function of both molecular functionality and weight. Although poly(ethylene glycol) (PEG) with abundant H-accepters exhibited high antiscaling efficiencies during static experiments, it displayed limited performance of mitigating silica scaling during MD and RO. Poly (ethylene glycol) diamine (PEGD), which has a PEG backbone but is terminated by two amino groups, was efficient to both hinder silicic acid polymerization and reduce water flux decline in MD and RO. Antiscalants enriched with H-donors, such as poly(ethylenimine) (PEI) and poly(amidoamine) (PAMAM), were effective of extending the water recovery of MD but conversely facilitated water flux decline of RO in the presence of supersaturated silica. Further analyses of silica scales formed on the membrane surfaces confirmed that the antiscalants interacted with silica via hydrogen bonding and showed that the presence of antiscalants governed the silica morphology. Our work indicates that discrepancy in antiscalant efficiency exists between static experiments and dynamic membrane filtration as well as between different membrane processes associated with silica scaling, providing valuable insights on the design principle and mechanisms of antiscalants tailored to silica scaling.
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Affiliation(s)
- Yiqun Yao
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States
| | - Xijia Ge
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States
| | - Yiming Yin
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States
| | - Ronny Minjarez
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States
| | - Tiezheng Tong
- Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, CO 80523, United States.
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4
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Nguyen BX, Sonea A, Warren JJ. Further Understanding the Roles of Solvent, Brønsted Acids, and Hydrogen Bonding in Iron Porphyrin-Mediated Carbon Dioxide Reduction. Inorg Chem 2023; 62:17602-17611. [PMID: 37847220 DOI: 10.1021/acs.inorgchem.3c01855] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Improving our understanding of how molecules and materials mediate the electrochemical reduction of carbon dioxide (CO2) to upgraded products is of great interest as a means to address climate change. A leading class of molecules that can facilitate the electrochemical conversion of CO2 to carbon monoxide (CO) is iron porphyrins. These molecules can have high rate constants for CO2-to-CO conversion; they are robust, and they rely on abundant and inexpensive synthetic building blocks. Important foundational work has been conducted using chloroiron 5,10,15,20-tetraphenylporphyrin (FeTPPCl) in N,N-dimethylformamide (DMF) solvent. A related and recent report points out that the corresponding perchlorate complex, FeTPPClO4, can have superior function due to its solubility in other organic solvents. However, the importance of hydrogen bonding and solvent effects was not discussed. Herein, we present a detailed kinetic study of the triflate (CF3SO3-) complex of FeTPP in DMF and in MeCN using a range of phenol Brønsted acid additives. We also detected the formation of Fe(III)TPP-phenolate complexes using cyclic voltammetry experiments. Importantly, our new analysis of apparent rate constants with different added phenols allows for a modification to the established mechanistic model for CO2-to-CO conversion. Critically, our improved model accounts for hydrogen bonding and solvent effects by using simple hydrogen bond acidity and basicity descriptors. We use this augmented model to rationalize function in other reported porphyrin systems and to make predictions about operational conditions that can enhance the CO2 reduction chemistry.
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Affiliation(s)
- Bach Xuan Nguyen
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, British Columbia, Canada
| | - Ana Sonea
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, British Columbia, Canada
| | - Jeffrey J Warren
- Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby V5A 1S6, British Columbia, Canada
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5
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Clark JA, Prabhu VM, Douglas JF. Molecular Dynamics Simulation of the Influence of Temperature and Salt on the Dynamic Hydration Layer in a Model Polyzwitterionic Polymer PAEDAPS. J Phys Chem B 2023; 127:8185-8198. [PMID: 37668318 PMCID: PMC10578162 DOI: 10.1021/acs.jpcb.3c03654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
We investigate the hydration of poly(3-[2-(acrylamido) ethyldimethylammonio] propanesulfonate) over a range of temperatures in pure water and with the inclusion of 0.1 mol/L NaCl using atomistic molecular dynamics simulation. Drawing on concepts drawn from the field of glass-forming liquids, we use the Debye-Waller parameter () for describing the water mobility gradient around the polybetaine backbone extending to an overall distance ≈18 Å. The water mobility in this layer is defined through the mean-square water molecule displacement at a time on the order of water's β-relaxation time. The brushlike topology of polybetaines leads to two regions in the dynamic hydration layer. The inner region of ≈10.5 Å is explored by pendant group conformational motions, and the outer region of ≈7.5 Å represents an extended layer of reduced water mobility relative to bulk water. The dynamic hydration layer extends far beyond the static hydration layer, adjacent to the polymer.
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Affiliation(s)
- Jennifer A. Clark
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Vivek M. Prabhu
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Jack F. Douglas
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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6
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Biswas R, Samanta K, Ghorai S, Maji S, Natarajan R. Conformationally Flexible Cleft Receptor for Chloride Anion Transport. ACS OMEGA 2023; 8:19625-19631. [PMID: 37305253 PMCID: PMC10249377 DOI: 10.1021/acsomega.3c01146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 04/25/2023] [Indexed: 06/13/2023]
Abstract
The design and synthesis of a cleft-shaped bis-diarylurea receptor for chloride anion transport is reported in this work. The receptor is based on the foldameric nature of N,N'-diphenylurea upon its dimethylation. The bis-diarylurea receptor exhibits a strong and selective affinity for chloride over bromide and iodide anions. A nanomolar quantity of the receptor efficiently transports the chloride across a lipid bilayer membrane as a 1:1 complex (EC50 = 5.23 nm). The work demonstrates the utility of the N,N'-dimethyl-N,N'-diphenylurea scaffold in anion recognition and transport.
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Affiliation(s)
- Raju Biswas
- Organic
& Medicinal Chemistry Division, CSIR-Indian
Institute of Chemical Biology, 4 Raja SC Mullick Road, Kolkata 700032, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Krishanu Samanta
- Organic
& Medicinal Chemistry Division, CSIR-Indian
Institute of Chemical Biology, 4 Raja SC Mullick Road, Kolkata 700032, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Sandipan Ghorai
- Organic
& Medicinal Chemistry Division, CSIR-Indian
Institute of Chemical Biology, 4 Raja SC Mullick Road, Kolkata 700032, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Suman Maji
- Organic
& Medicinal Chemistry Division, CSIR-Indian
Institute of Chemical Biology, 4 Raja SC Mullick Road, Kolkata 700032, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ramalingam Natarajan
- Organic
& Medicinal Chemistry Division, CSIR-Indian
Institute of Chemical Biology, 4 Raja SC Mullick Road, Kolkata 700032, India
- Academy
of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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7
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Zaitseva S, Prescimone A, Köhler V. Enantioselective Allylation of Stereogenic Nitrogen Centers. Org Lett 2023; 25:1649-1654. [PMID: 36881477 PMCID: PMC10028698 DOI: 10.1021/acs.orglett.3c00195] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Most tertiary amines with a stereogenic nitrogen center undergo rapid racemization at room temperature. Consequently, the quaternization of amines under dynamic kinetic resolution seems feasible. N-Methyl tetrahydroisoquinolines are converted into configurationally stable ammonium ions by Pd-catalyzed allylic alkylation. The optimization of conditions and the evaluation of the substrate scope enabled high conversions and an enantiomeric ratio of up to 10:90. We report here the first examples for the enantioselective catalytic synthesis of chiral ammonium ions.
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Affiliation(s)
- Snizhana Zaitseva
- Department of Chemistry, University of Basel, Mattenstrasse 22, 4058 Basel, Switzerland
| | - Alessandro Prescimone
- Department of Chemistry, University of Basel, Mattenstrasse 22, 4058 Basel, Switzerland
| | - Valentin Köhler
- Department of Chemistry, University of Basel, Mattenstrasse 22, 4058 Basel, Switzerland
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8
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Krevert CS, Gunkel L, Haese C, Hunger J. Ion-specific binding of cations to the carboxylate and of anions to the amide of alanylalanine. Commun Chem 2022; 5:173. [PMID: 36697920 PMCID: PMC9814750 DOI: 10.1038/s42004-022-00789-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 11/30/2022] [Indexed: 12/24/2022] Open
Abstract
Studies of ion-specific effects on oligopeptides have aided our understanding of Hofmeister effects on proteins, yet the use of different model peptides and different experimental sensitivities have led to conflicting conclusions. To resolve these controversies, we study a small model peptide, L-Alanyl-L-alanine (2Ala), carrying all fundamental chemical protein motifs: C-terminus, amide bond, and N-terminus. We elucidate the effect of GdmCl, LiCl, KCl, KI, and KSCN by combining dielectric relaxation, nuclear magnetic resonance (1H-NMR), and (two-dimensional) infrared spectroscopy. Our dielectric results show that all ions reduce the rotational mobility of 2Ala, yet the magnitude of the reduction is larger for denaturing cations than for anions. The NMR chemical shifts of the amide group are particularly sensitive to denaturing anions, indicative of anion-amide interactions. Infrared experiments reveal that LiCl alters the spectral homogeneity and dynamics of the carboxylate, but not the amide group. Interaction of LiCl with the negatively charged pole of 2Ala, the COO- group, can explain the marked cationic effect on dipolar rotation, while interaction of anions between the poles, at the amide, only weakly perturbs dipolar dynamics. As such, our results provide a unifying view on ions' preferential interaction sites at 2Ala and help rationalize Hofmeister effects on proteins.
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Affiliation(s)
- Carola Sophie Krevert
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Lucas Gunkel
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Constantin Haese
- grid.419547.a0000 0001 1010 1663Department of Molecular Electronics, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Johannes Hunger
- grid.419547.a0000 0001 1010 1663Department of Molecular Spectroscopy, Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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9
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Storer MC, Hunter CA. The surface site interaction point approach to non-covalent interactions. Chem Soc Rev 2022; 51:10064-10082. [PMID: 36412990 DOI: 10.1039/d2cs00701k] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The functional properties of molecular systems are generally determined by the sum of many weak non-covalent interactions, and therefore methods for predicting the relative magnitudes of these interactions is fundamental to understanding the relationship between function and structure in chemistry, biology and materials science. This review focuses on the Surface Site Interaction Point (SSIP) approach which describes molecules as a set of points that capture the properties of all possible non-covalent interactions that the molecule might make with another molecule. The first half of the review focuses on the empirical non-covalent interaction parameters, α and β, and provides simple rules of thumb to estimate free energy changes for interactions between different types of functional group. These parameters have been used to have been used to establish a quantitative understanding of the role of solvent in solution phase equilibria, and to describe non-covalent interactions at the interface between macroscopic surfaces as well as in the solid state. The second half of the review focuses on a computational approach for obtaining SSIPs and applications in multi-component systems where many different interactions compete. Ab initio calculation of the Molecular Electrostatic Potential (MEP) surface is used to derive an SSIP description of a molecule, where each SSIP is assigned a value equivalent to the corresponding empirical parameter, α or β. By considering the free energies of all possible pairing interactions between all SSIPs in a molecular ensemble, it is possible to calculate the speciation of all intermolecular interactions and hence predict thermodynamic properties using the SSIMPLE algorithm. SSIPs have been used to describe both the solution phase and the solid state and provide accurate predictions of partition coefficients, solvent effects on association constants for formation of intermolecular complexes, and the probability of cocrystal formation. SSIPs represent a simple and intuitive tool for describing the relationship between chemical structure and non-covalent interactions with sufficient accuracy to understand and predict the properties of complex molecular ensembles without the need for computationally expensive simulations.
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Affiliation(s)
- Maria Chiara Storer
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
| | - Christopher A Hunter
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
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10
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Brar NK, Brown RT, Shahbaz K, Hunt PA, Weber CC. Guanidinium solvents with exceptional hydrogen bond donating abilities. Chem Commun (Camb) 2022; 58:3505-3508. [PMID: 35195124 DOI: 10.1039/d1cc06938a] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Guanidinium chloride-based solvents have been prepared using deep eutectic solvent principles. Strong hydrogen-bond (H-bond) donating abilities are established based on a range of measures of solvent polarity, including a novel 31P NMR chemical shift method. The physical properties and origin of the strong H-bonding ability of these solvents have been explored.
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Affiliation(s)
- Navneet K Brar
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand. .,MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - Roland T Brown
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand. .,MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - Kaveh Shahbaz
- Department of Chemical and Materials Engineering, University of Auckland, Auckland, New Zealand
| | - Patricia A Hunt
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.,School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington, New Zealand
| | - Cameron C Weber
- School of Chemical Sciences, University of Auckland, Auckland, New Zealand. .,MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
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11
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LTM-TCM: A Comprehensive Database for the Linking of Traditional Chinese Medicine with Modern Medicine at Molecular and Phenotypic Levels. Pharmacol Res 2022; 178:106185. [DOI: 10.1016/j.phrs.2022.106185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 03/11/2022] [Accepted: 03/12/2022] [Indexed: 02/07/2023]
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12
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Wales SM, Morris DTJ, Clayden J. Reversible Capture and Release of a Ligand Mediated by a Long-Range Relayed Polarity Switch in a Urea Oligomer. J Am Chem Soc 2022; 144:2841-2846. [PMID: 35142216 PMCID: PMC9097480 DOI: 10.1021/jacs.1c11928] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
![]()
Ethylene-bridged
oligoureas characterized by a continuous, switchable
chain of hydrogen bonds and carrying a binding site (an N,N′-disubstituted
urea) for a hydrogen-bond-accepting ligand (a phosphine oxide) were
synthesized. These oligomers show stronger ligand binding when the
binding site is located at the hydrogen-bond-donating terminus than
when the same binding site is at the hydrogen-bond-accepting terminus.
An acidic group at the terminus remote from the binding site allows
hydrogen bond polarity, and hence ligand binding ability, to be controlled
remotely by a deprotonation/reprotonation cycle. Addition of base
induces a remote conformational change that is relayed through up
to five urea linkages, reducing the ability of the binding site to
retain an intermolecular association to its ligand, which is consequently
released into solution. Reprotonation returns the polarity of the
oligomer to its original directionality, restoring the function of
the remote binding site, which consequently recaptures the ligand.
This is the first example of a synthetic molecular structure that
relays intermolecular binding information, and these “dynamic
foldamer” structures are prototypes of components for chemical
systems capable of controlling chemical function from a distance.
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Affiliation(s)
- Steven M Wales
- School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - David T J Morris
- School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
| | - Jonathan Clayden
- School of Chemistry, University of Bristol, Bristol BS8 1TS, U.K
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13
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Badiani VM, Cobb SJ, Wagner A, Oliveira AR, Zacarias S, Pereira IAC, Reisner E. Elucidating Film Loss and the Role of Hydrogen Bonding of Adsorbed Redox Enzymes by Electrochemical Quartz Crystal Microbalance Analysis. ACS Catal 2022; 12:1886-1897. [PMID: 35573129 PMCID: PMC9097293 DOI: 10.1021/acscatal.1c04317] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/13/2021] [Indexed: 12/17/2022]
Abstract
![]()
The immobilization of redox enzymes
on electrodes enables the efficient
and selective electrocatalysis of useful reactions such as the reversible
interconversion of dihydrogen (H2) to protons (H+) and formate to carbon dioxide (CO2) with hydrogenase
(H2ase) and formate dehydrogenase (FDH), respectively.
However, their immobilization on electrodes to produce electroactive
protein films for direct electron transfer (DET) at the protein–electrode
interface is not well understood, and the reasons for their activity
loss remain vague, limiting their performance often to hour timescales.
Here, we report the immobilization of [NiFeSe]-H2ase and
[W]-FDH from Desulfovibrio vulgaris Hildenborough on a range of charged and neutral self-assembled monolayer
(SAM)-modified gold electrodes with varying hydrogen bond (H-bond)
donor capabilities. The key factors dominating the activity and stability
of the immobilized enzymes are determined using protein film voltammetry
(PFV), chronoamperometry (CA), and electrochemical quartz crystal
microbalance (E-QCM) analysis. Electrostatic and H-bonding interactions
are resolved, with electrostatic interactions responsible for enzyme
orientation while enzyme desorption is strongly limited when H-bonding
is present at the enzyme–electrode interface. Conversely, enzyme
stability is drastically reduced in the absence of H-bonding, and
desorptive enzyme loss is confirmed as the main reason for activity
decay by E-QCM during CA. This study provides insights into the possible
reasons for the reduced activity of immobilized redox enzymes and
the role of film loss, particularly H-bonding, in stabilizing bioelectrode
performance, promoting avenues for future improvements in bioelectrocatalysis.
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Affiliation(s)
- Vivek M. Badiani
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
- Cambridge Graphene Centre, University of Cambridge, Cambridge CB3 0FA, U.K
| | - Samuel J. Cobb
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Andreas Wagner
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
| | - Ana Rita Oliveira
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade NOVA de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Sónia Zacarias
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade NOVA de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Inês A. C. Pereira
- Instituto de Tecnologia Química e Biológica António Xavier (ITQB NOVA), Universidade NOVA de Lisboa, Av. da República, 2780-157 Oeiras, Portugal
| | - Erwin Reisner
- Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K
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14
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Roy J, Chakraborty P, Paramasivam G, Natarajan G, Pradeep T. Gas phase ion chemistry of titanium-oxofullerene with ligated solvents. Phys Chem Chem Phys 2022; 24:2332-2343. [PMID: 35018393 DOI: 10.1039/d1cp04716g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We investigated the gas phase fragmentation events of highly symmetric fullerene-like (FN-like) titanium oxo-cluster anions, [H12Ti42O60(OCH3)42(HOCH3)10(H2O)2]2- (1) and [H7Ti42O60(OCH3)42(HOCH3)10(H2O)3]1- (2). These oxo-clusters contain a closed cage Ti42O60 core, protected by a specific number of methoxy, methanol, and water molecules acting as ligands. These dianionic and monoanionic species were generated in the gas phase by electrospray ionization of the H6[Ti42(μ3-O)60(OiPr)42(OH)12] (TOF) cluster in methanol. Collision induced dissociation studies of 1 revealed that upon increasing the collision energy, the protecting ligands were stripped off first, and [Ti41O58]2- was formed as the first fragment from the Ti42O60 core. Thereafter, systematic TiO2 losses were observed giving rise to subsequent fragments like [Ti40O56]2-, [Ti39O54]2-, [Ti38O52]2-, etc. Similar fragments were also observed for monoanionic species 2 as well. Systematic 23 TiO2 losses were observed, which were followed by complete shattering of the cage. We also carried out computational studies using density functional theory (DFT) to investigate the structures and fragmentation mechanism. The fragmentation of TOF was comparable to the fragmentation of C60 ions, where systematic C2 losses were observed. We believe that this is a consequence of topological similarity. The present study provides valuable insights into the structural constitution of TOF clusters and stability of the parent as well as the resulting cage-fragments in the gas phase.
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Affiliation(s)
- Jayoti Roy
- DST Unit of Nanoscience (DST UNS) & Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Papri Chakraborty
- DST Unit of Nanoscience (DST UNS) & Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Ganesan Paramasivam
- DST Unit of Nanoscience (DST UNS) & Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
| | - Ganapati Natarajan
- International Centre for Clean Water (ICCW), IIT Madras Research Park, Taramani, Chennai 6000113, India
| | - Thalappil Pradeep
- DST Unit of Nanoscience (DST UNS) & Thematic Unit of Excellence (TUE), Department of Chemistry, Indian Institute of Technology Madras, Chennai 600036, India.
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15
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Corner SC, Goodwin CAP, Ortu F, Evans P, Zhang H, Gransbury GK, Whitehead GFS, Mills DP. Synthesis of heteroleptic yttrium and dysprosium 1,2,4-tris(trimethylsilyl)cyclopentadienyl complexes. Aust J Chem 2022. [DOI: 10.1071/ch21314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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16
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McLaughlin C, Bitai J, Barber LJ, Slawin AMZ, Smith AD. Catalytic enantioselective synthesis of 1,4-dihydropyridines via the addition of C(1)-ammonium enolates to pyridinium salts. Chem Sci 2021; 12:12001-12011. [PMID: 34667566 PMCID: PMC8457386 DOI: 10.1039/d1sc03860e] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/05/2021] [Indexed: 12/30/2022] Open
Abstract
The regio- and stereoselective addition of C(1)-ammonium enolates - generated in situ from aryl esters and the isothiourea catalyst (R)-BTM - to pyridinium salts bearing an electron withdrawing substituent in the 3-position allows the synthesis of a range of enantioenriched 1,4-dihydropyridines. This represents the first organocatalytic approach to pyridine dearomatisation using pronucleophiles at the carboxylic acid oxidation level. Optimisation studies revealed a significant solvent dependency upon product enantioselectivity, with only toluene providing significant asymmetric induction. Using DABCO as a base also proved beneficial for product enantioselectivity, while investigations into the nature of the counterion showed that co-ordinating bromide or chloride substrates led to higher product er than the corresponding tetrafluoroborate or hexafluorophosphate. The scope and limitations of this process are developed, with enantioselective addition to 3-cyano- or 3-sulfonylpyridinium salts giving the corresponding 1,4-dihydropyridines (15 examples, up to 95 : 5 dr and 98 : 2 er).
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Affiliation(s)
- Calum McLaughlin
- EaStCHEM, School of Chemistry, University of St Andrews St Andrews Fife KY16 9ST UK
| | - Jacqueline Bitai
- EaStCHEM, School of Chemistry, University of St Andrews St Andrews Fife KY16 9ST UK
| | - Lydia J Barber
- EaStCHEM, School of Chemistry, University of St Andrews St Andrews Fife KY16 9ST UK
| | - Alexandra M Z Slawin
- EaStCHEM, School of Chemistry, University of St Andrews St Andrews Fife KY16 9ST UK
| | - Andrew D Smith
- EaStCHEM, School of Chemistry, University of St Andrews St Andrews Fife KY16 9ST UK
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17
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Walsh MP, Phelps JM, Lennon ME, Yufit DS, Kitching MO. Enantioselective synthesis of ammonium cations. Nature 2021; 597:70-76. [PMID: 34471272 DOI: 10.1038/s41586-021-03735-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 06/17/2021] [Indexed: 02/07/2023]
Abstract
Control of molecular chirality is a fundamental challenge in organic synthesis. Whereas methods to construct carbon stereocentres enantioselectively are well established, routes to synthesize enriched heteroatomic stereocentres have garnered less attention1-5. Of those atoms commonly present in organic molecules, nitrogen is the most difficult to control stereochemically. Although a limited number of resolution processes have been demonstrated6-8, no general methodology exists to enantioselectively prepare a nitrogen stereocentre. Here we show that control of the chirality of ammonium cations is easily achieved through a supramolecular recognition process. By combining enantioselective ammonium recognition mediated by 1,1'-bi-2-naphthol scaffolds with conditions that allow the nitrogen stereocentre to racemize, chiral ammonium cations can be produced in excellent yields and selectivities. Mechanistic investigations demonstrate that, through a combination of solution and solid-phase recognition, a thermodynamically driven adductive crystallization process is responsible for the observed selectivity. Distinct from processes based on dynamic and kinetic resolution, which are under kinetic control, this allows for increased selectivity over time by a self-corrective process. The importance of nitrogen stereocentres can be revealed through a stereoselective supramolecular recognition, which is not possible with naturally occurring pseudoenantiomeric Cinchona alkaloids. With practical access to the enantiomeric forms of ammonium cations, this previously ignored stereocentre is now available to be explored.
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Affiliation(s)
- Mark P Walsh
- Department of Chemistry, Durham University, Durham, UK
| | | | - Marc E Lennon
- Department of Chemistry, Durham University, Durham, UK
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18
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Classification of total number of hydrogen bonds in drugs for suppressing virus. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2021.102704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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19
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Tian M, Zhang K, Zhang Y, Zhou H, Yuan Z, Lu C. Design of ratiometric monoaromatic fluorescence probe via modulating intramolecular hydrogen bonding: A case study of alkaline phosphatase sensing. Anal Chim Acta 2021; 1143:144-156. [PMID: 33384112 DOI: 10.1016/j.aca.2020.11.048] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/27/2020] [Accepted: 11/29/2020] [Indexed: 11/19/2022]
Abstract
Monoaromatic molecules are a category of molecules containing a single aromatic ring which generally emit light in the ultraviolet (UV) region. Despite their facile preparation, the UV emission greatly limits their application as organic probes. In this study, we developed a general method to red shift the emission of monoaromatic molecules. Significant fluorescence red-shift (∼100 nm per intramolecular hydrogen bonding) can be achieved by introducing intramolecular hydrogen bonding units to benzene, a typical monoaromatic molecule. Upon increasing the number of hydrogen bonding units on the benzene ring, UV, blue, and green emissions are screened, which are switchable by simply breaking/restoration the intramolecular hydrogen bonding. As a demonstration, with the breaking of one intramolecular H-bonding, the green emission (λemmax = 533 nm) of 2,5-dihydroxyterephthalic acid (DHTA) changed to cyan (λemmax = 463 nm) upon the formation of its phosphorylated form (denoted as PDHTA), which, in the presence of alkaline phosphatase (ALP), hydrolyzed and recovered the green emission. By taking advantage of the switchable emission colors, ratiometric in vitro and endogenous ALP sensing was achieved. This general approach offers a great promise to develop organic probes with tunable emissions for fluorescence analysis and imaging by different intramolecular hydrogen bonding.
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Affiliation(s)
- Mingce Tian
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Kai Zhang
- College of Preclinical Medicine, Southwest Medical University, Luzhou, 646000, China.
| | - Yanjun Zhang
- College of Preclinical Medicine, Southwest Medical University, Luzhou, 646000, China
| | - He Zhou
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Zhiqin Yuan
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
| | - Chao Lu
- State Key Laboratory of Chemical Resource Engineering, College of Chemistry, Beijing University of Chemical Technology, Beijing, 100029, China.
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20
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Kinney ZJ, Rheingold AL, Protasiewicz JD. Preferential N-H⋯:C[double bond splayed right] hydrogen bonding involving ditopic NH-containing systems and N-heterocyclic carbenes. RSC Adv 2020; 10:42164-42171. [PMID: 35516763 PMCID: PMC9057831 DOI: 10.1039/d0ra08490e] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/05/2020] [Indexed: 11/21/2022] Open
Abstract
Hydrogen bonding plays a critical role in maintaining order and structure in complex biological and synthetic systems. N-heterocyclic carbenes (NHCs) represent one of the most versatile tools in the synthetic chemistry toolbox, yet their potential as neutral carbon hydrogen bond acceptors remains underexplored. This report investigates this capability in a strategic manner, wherein carbene-based hydrogen bonding can be assessed by use of ditopic NH-containing molecules. N-H bonds are unique as there are three established reaction modes with carbenes: non-traditional hydrogen bonding adducts (X-H⋯:C[double bond splayed right]), salts arising from proton transfer ([H-C[double bond splayed right]]+[X]-), or amines from insertion of the carbene into the N-H bond. Yet, there are no established rules to predict product distributions or the strength of these associations. Here we seek to correlate the hydrogen bond strength of symmetric and asymmetric ditopic secondary amines with 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene (IPr, a representative NHC). In symmetric and asymmetric ditopic amine adducts both the solid-state (hydrogen bond lengths, NHC interior angles) and solution-state (1H Δδ of NH signals, 13C signals of carbenic carbon) can be related to the pK a of the parent amine.
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Affiliation(s)
- Zacharias J Kinney
- Department of Chemistry, Case Western Reserve University Cleveland Ohio 44106 USA
| | - Arnold L Rheingold
- Department of Chemistry and Biochemistry, University of California La Jolla San Diego California 92093 USA
| | - John D Protasiewicz
- Department of Chemistry, Case Western Reserve University Cleveland Ohio 44106 USA
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21
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Axelsson A, Hammarvid E, Rahm M, Sundén H. DBU‐Catalyzed Ring‐Opening and Retro‐Claisen Fragmentation of Dihydropyranones. European J Org Chem 2020. [DOI: 10.1002/ejoc.202000858] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Anton Axelsson
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Emmelie Hammarvid
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Martin Rahm
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
| | - Henrik Sundén
- Chemistry and Chemical Engineering Chalmers University of Technology Kemivägen 10 412 96 Göteborg Sweden
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22
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Driver MD, Williamson MJ, Cook JL, Hunter CA. Functional group interaction profiles: a general treatment of solvent effects on non-covalent interactions. Chem Sci 2020; 11:4456-4466. [PMID: 34122903 PMCID: PMC8159447 DOI: 10.1039/d0sc01288b] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Solvation has profound effects on the behaviour of supramolecular systems, but the effects can be difficult to predict even at a qualitative level. Functional group interaction profiles (FGIPs) provide a simple visual method for understanding how solvent affects the free energy contribution due to a single point interaction, such as a hydrogen bond, between two solute functional groups. A generalised theoretical approach has been developed, which allows calculation of FGIPs for any solvent or solvent mixture, and FGIPs for 300 different solvents have been produced, providing a comprehensive description of solvent effects on non-covalent chemistry. The free energy calculations have been validated using experimental measurements of association constants for hydrogen bonded complexes in multiple solvent mixtures. The calculated FGIPs provide good descriptions of the solvation of polar solutes, solvophobic interactions between non-polar solutes in polar solvents like water, and preferential solvation in solvent mixtures. Applications are explored of the use of FGIPs in drug design, for optimising receptor-ligand interactions, and in enantioselective catalysis for solvent selection to optimise selectivity.
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Affiliation(s)
- Mark D Driver
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK +44 (0)1223 336710
| | - Mark J Williamson
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK +44 (0)1223 336710
| | - Joanne L Cook
- Department of Chemistry, University of Sheffield Sheffield S3 7HF UK
| | - Christopher A Hunter
- Department of Chemistry, University of Cambridge Lensfield Road Cambridge CB2 1EW UK +44 (0)1223 336710
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23
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Kolodina AA, Tsaturyan AA, Galkina MS, Borodkina IG, Vetrova EV, Demidov OP, Berezhnaya AG, Metelitsa AV. 6,7‐Dihydro‐5
H
‐1,2,4‐triazolo[3,4‐
b
][1,3,4]thiadiazine Ring Cleavage and Tautomerism of the Products: Experimental and Theoretical Study. ChemistrySelect 2020. [DOI: 10.1002/slct.202000732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Alexandra A. Kolodina
- Institute of Physical and Organic ChemistrySouthern Federal University 194/2 Stachki St. Rostov on Don 344090 Russian Federation
| | - Arshak A. Tsaturyan
- Institute of Physical and Organic ChemistrySouthern Federal University 194/2 Stachki St. Rostov on Don 344090 Russian Federation
| | - Maria S. Galkina
- Institute of Physical and Organic ChemistrySouthern Federal University 194/2 Stachki St. Rostov on Don 344090 Russian Federation
| | - Inna G. Borodkina
- Institute of Physical and Organic ChemistrySouthern Federal University 194/2 Stachki St. Rostov on Don 344090 Russian Federation
| | - Elena V. Vetrova
- Institute of Physical and Organic ChemistrySouthern Federal University 194/2 Stachki St. Rostov on Don 344090 Russian Federation
| | - Oleg P. Demidov
- Department of Chemistry of the Institutes of Mathematics and Natural SciencesNorth Caucasus Federal University 1a Pushkina St. Stavropol 355009 Russian Federation
| | - Alexandra G. Berezhnaya
- Faculty of ChemistrySouthern Federal University 7 Zorge St Rostov-on-Don 344090 Russian Federation
| | - Anatoly V. Metelitsa
- Institute of Physical and Organic ChemistrySouthern Federal University 194/2 Stachki St. Rostov on Don 344090 Russian Federation
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24
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Abstract
Gold nanoclusters (AuNCs) with well-defined atomically precise structures present promising emissive prospects for excellent biocompatibility and optical properties. However, the relatively low luminescence efficiency in solutions for most AuNCs is still a perplexing issue to be resolved. In this study, a facile supramolecular strategy was developed to rigidify the surface of FGGC-AuNCs by modifying transition rates in excited states via host-guest self-assembly between cucurbiturils (CBs) and FGGC (Phe-Gly-Gly-Cys peptide). In aqueous solutions, CB/FGGC-AuNCs presented an extremely enhanced red phosphorescence emission with a quantum yield (QY) of 51% for CB[7] and 39% for CB[8], while simple FGGC-AuNCs only showed a weak emission with a QY of 7.5%. Furthermore, CB[7]/FGGC-AuNCs showed excellent results in live cell luminescence imaging for A549 cancer cells. Our study demonstrates that host-guest self-assembly assisted by macrocycles is a facile and effective tool to non-covalently modify and adjust optical properties of nanostructures on ultra-small scales.
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Affiliation(s)
- Tao Jiang
- Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science & Technology 130 Meilong Road Shanghai 200237 China
| | - Guojuan Qu
- Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science & Technology 130 Meilong Road Shanghai 200237 China
| | - Jie Wang
- Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science & Technology 130 Meilong Road Shanghai 200237 China
| | - Xiang Ma
- Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science & Technology 130 Meilong Road Shanghai 200237 China
| | - He Tian
- Key Laboratory for Advanced Materials, Feringa Nobel Prize Scientist Joint Research Center, Institute of Fine Chemicals, School of Chemistry and Molecular Engineering, East China University of Science & Technology 130 Meilong Road Shanghai 200237 China
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25
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Schindl A, Hawker RR, Schaffarczyk McHale KS, Liu KTC, Morris DC, Hsieh AY, Gilbert A, Prescott SW, Haines RS, Croft AK, Harper JB, Jäger CM. Controlling the outcome of S N2 reactions in ionic liquids: from rational data set design to predictive linear regression models. Phys Chem Chem Phys 2020; 22:23009-23018. [PMID: 33043942 DOI: 10.1039/d0cp04224b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Rate constants for a bimolecular nucleophilic substitution (SN2) process in a range of ionic liquids are correlated with calculated parameters associated with the charge localisation on the cation of the ionic liquid (including the molecular electrostatic potential). Simple linear regression models proved effective, though the interdependency of the descriptors needs to be taken into account when considering generality. A series of ionic liquids were then prepared and evaluated as solvents for the same process; this data set was rationally chosen to incorporate homologous series (to evaluate systematic variation) and functionalities not available in the original data set. These new data were used to evaluate and refine the original models, which were expanded to include simple artificial neural networks. Along with showing the importance of an appropriate data set and the perils of overfitting, the work demonstrates that such models can be used to reliably predict ionic liquid solvent effects on an organic process, within the limits of the data set.
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Affiliation(s)
- Alexandra Schindl
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Rebecca R Hawker
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | | | - Kenny T-C Liu
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Daniel C Morris
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia. and School of Chemical Engineering, University of New South Wales, UNSW Sydney, 2052, Australia
| | - Andrew Y Hsieh
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Alyssa Gilbert
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Stuart W Prescott
- School of Chemical Engineering, University of New South Wales, UNSW Sydney, 2052, Australia
| | - Ronald S Haines
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Anna K Croft
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
| | - Jason B Harper
- School of Chemistry, University of New South Wales, UNSW Sydney, 2052, Australia.
| | - Christof M Jäger
- Department of Chemical and Environmental Engineering, University of Nottingham, Nottingham NG7 2RD, UK.
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26
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Wijaya AW, Nguyen AI, Roe LT, Butterfoss GL, Spencer RK, Li NK, Zuckermann RN. Cooperative Intramolecular Hydrogen Bonding Strongly Enforces cis-Peptoid Folding. J Am Chem Soc 2019; 141:19436-19447. [DOI: 10.1021/jacs.9b10497] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Affiliation(s)
- Andrew W. Wijaya
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Andy I. Nguyen
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Leah T. Roe
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Glenn L. Butterfoss
- Center for Genomics and Systems Biology, New York University Abu Dhabi, Abu Dhabi, United Arab Emirates
| | - Ryan K. Spencer
- Department of Chemistry, Department of Chemical Engineering & Material Science, University of California, Irvine, California 92697, United States
| | - Nan K. Li
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
| | - Ronald N. Zuckermann
- The Molecular Foundry, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
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