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Delarue Bizzini L, Zwick P, Mayor M. Preparation of Unsymmetrical Disulfides from Thioacetates and Thiosulfonates. European J Org Chem 2019. [DOI: 10.1002/ejoc.201901283] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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52
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Luo YC, Chu KL, Shi JY, Wu DJ, Wang XD, Mayor M, Su CY. Heterogenization of Photochemical Molecular Devices: Embedding a Metal-Organic Cage into a ZIF-8-Derived Matrix To Promote Proton and Electron Transfer. J Am Chem Soc 2019; 141:13057-13065. [PMID: 31343866 DOI: 10.1021/jacs.9b03981] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Application of a molecular catalyst in artificial photosynthesis is confronted with challenges such as rapid deactivation due to photodegradation or detrimental aggregation in harsh conditions. In this work, a metal-organic cage [Pd6(RuL3)8]28+ (MOC-16), characteristic of a photochemical molecular device (PMD) concurrently integrating eight Ru2+ light-harvesting centers and six Pd2+ catalytic centers for efficient homogeneous H2 production, is successfully heterogenized through incorporation into a metal-organic framework (MOF) of ZIF-8 and then transformed into a carbonate matrix of Znx(MeIm)x(CO3)x (CZIF), leading to hybridized MOC-16@CZIF. This MOC@MOF integrated photocatalyst inherits a highly efficient and directional electron transfer in the picosecond domain of MOC-16 and possesses one order increased microsecond magnitude of the triplet excited-state electron in comparison to that of the primitive MOC-16. The carbonate CZIF matrix endows MOC-16@CZIF with water wettability, serving as a proton relay to facilitate proton delivery by virtue of H2O as proton carriers. Electron transfer during the photocatalytic process is also enhanced by infiltration of a sacrificial agent of BIH into the CZIF matrix to promote conductivity, owing to its strong reducing ability to induce free charge carriers. These synergistic effects contribute to the extra high activity for H2 generation, making the turnover frequency of this heterogeneous MOC-16@CZIF photocatalyst maintain a level of ∼0.4 H2·s-1, increased by 50-fold over that of a homogeneous PMD. Meanwhile, it is robust enough to tolerate harsh reaction conditions, presenting an unprecedented heterogenization example of homogeneous PMD with a MOF-derived matrix to mimic catalytic features of a natural photosystem, which may shed light on the design of multifunctional PMD@MOF materials to expand the number of molecular catalysts for practical application in artificial photosynthesis.
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El Abbassi M, Zwick P, Rates A, Stefani D, Prescimone A, Mayor M, van der Zant HSJ, Dulić D. Unravelling the conductance path through single-porphyrin junctions. Chem Sci 2019; 10:8299-8305. [PMID: 31803408 PMCID: PMC6853084 DOI: 10.1039/c9sc02497b] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/30/2019] [Indexed: 01/29/2023] Open
Abstract
By studying transport through seven structurally related porphyrin derivatives with a machine learning algorithm we could identify and distinguish three different electronic paths.
Porphyrin derivatives are key components in natural machinery enabling us to store sunlight as chemical energy. In spite of their prominent role in cascades separating electrical charges and their potential as sensitizers in molecular devices, reports concerning their electronic transport characteristics are inconsistent. Here we report a systematic investigation of electronic transport paths through single porphyrin junctions. The transport through seven structurally related porphyrin derivatives was repeatedly measured in an automatized mechanically controlled break-junction set-up and the recorded data were analyzed by an unsupervised clustering algorithm. The correlation between the appearances of similar clusters in particular sub-sets of the porphyrins with a common structural motif allowed us to assign the corresponding current path. The small series of model porphyrins allowed us to identify and distinguish three different electronic paths covering more than four orders of magnitude in conductance.
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Abstract
Weaving is an old technique producing fabric materials by interlocking yarns, which we appreciate every day by wearing textiles. The splendid mechanical features of these macroscopic interwoven structures such as stability, flexibility, and shape adaptability raised the question whether
or not such properties might also be observed on a molecular level. In this article, molecular analogues to textiles are discussed and strategies to molecular weaves are presented. While there are impressive structural similarities between the macroscopic and the molecular world, molecular
textiles consisting of interwoven linear polymers remain a challenge. The scope of the article ranges from discrete superstructures like Solomon knots, over deoxyribonucleic acid (DNA) based nanoscale patterns and interwoven 2D sheets of coordination polymers, to weaving strategies
interlinking small organic precursors.
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Šebera J, Lindner M, Gasior J, Mészáros G, Fuhr O, Mayor M, Valášek M, Kolivoška V, Hromadová M. Tuning the contact conductance of anchoring groups in single molecule junctions by molecular design. NANOSCALE 2019; 11:12959-12964. [PMID: 31259338 DOI: 10.1039/c9nr04071d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A tetraphenylmethane tripod functionalized with three thiol moieties in the para position can serve as a supporting platform for functional molecular electronic elements. A combined experimental scanning tunneling microscopy break junction technique with theoretical approaches based on density functional theory and non-equilibrium Green's function formalism was used for detailed charge transport analysis to find configurations, geometries and charge transport pathways in the molecular junctions of single molecule oligo-1,4-phenylene conductors containing this tripodal anchoring group. The effect of molecular length (n = 1 to 4 repeating phenylene units) on the charge transport properties and junction configurations is addressed. The number of covalent attachments between the electrode and the tripodal platform changes with n affecting the contact conductance of the junction. The longest homologue n = 4 adopts an upright configuration with all three para thiolate moieties of the tripod attached to the gold electrode. The contact conductance of the tetraphenylmethane tripod substituted by thiols in the para position is higher than that substituted in the meta position. Such molecular arrangement is highly conducting and allows well-defined directional positioning of a variety of functional groups.
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Aeschi Y, Jucker L, Häussinger D, Mayor M. Slow Formation of Pseudorotaxanes in Water. European J Org Chem 2019. [DOI: 10.1002/ejoc.201801864] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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57
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Weiland KJ, Gallego A, Mayor M. Front Cover: Beyond Simple Substitution Patterns - Symmetrically Tetrasubstituted [2.2]Paracyclophanes as 3D Functional Materials (Eur. J. Org. Chem. 20/2019). European J Org Chem 2019. [DOI: 10.1002/ejoc.201900683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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58
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Galanti A, Santoro J, Mannancherry R, Duez Q, Diez-Cabanes V, Valášek M, De Winter J, Cornil J, Gerbaux P, Mayor M, Samorì P. A New Class of Rigid Multi(azobenzene) Switches Featuring Electronic Decoupling: Unravelling the Isomerization in Individual Photochromes. J Am Chem Soc 2019; 141:9273-9283. [DOI: 10.1021/jacs.9b02544] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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59
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Homberg J, Lindner M, Gerhard L, Edelmann K, Frauhammer T, Nahas Y, Valášek M, Mayor M, Wulfhekel W. Six state molecular revolver mounted on a rigid platform. NANOSCALE 2019; 11:9015-9022. [PMID: 31020977 DOI: 10.1039/c9nr00259f] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The rotation of entire molecules or large moieties happens at 100 ps time scales and the transition process itself is experimentally inaccessible to scanning probe techniques. However, the reversible switching of a molecule between more than two metastable states allows to assign a rotational switching direction. Rotational switching is a phenomenon that is particularly interesting with regard to possible applications in molecular motors. In this work, single tetraphenylmethane molecules deposited on a Au(111) surface were studied in a low temperature scanning tunneling microscope (STM). These molecules comprise rotational axes mounted on a tripodal sulfur-anchored stand and with the STM tip, we were able to induce transitions between six rotational states of the molecular motif. We were able to identify critical parameters for the onset of rotational switching and to characterize the influence of the local environment. The subtle difference between fcc and hcp stacking and the rotational state of neighboring molecules clearly influence the population of the rotational states.
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Mannancherry R, Devereux M, Häussinger D, Mayor M. Molecular Ansa-Basket: Synthesis of Inherently Chiral All-Carbon [12](1,6)Pyrenophane. J Org Chem 2019; 84:5271-5276. [PMID: 30945543 DOI: 10.1021/acs.joc.9b00255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The synthesis of inherently chiral all-carbon C2-symmetric [12](1,6)pyrenophane 1 is reported. The cyclophane 1 was obtained via a ring-closing alkyne metathesis reaction using Mortreux's catalyst molybdenum hexacarbonyl and 2-fluorophenol as a phenol additive. The M and P enantiomers of the all-carbon pyrenophane 1 were demonstrated to be very stable in their enantiopure form even upon prolonged heating at 200 °C. [12](1,6)Pyrenophane-6-yne 1 was fully characterized by high-resolution mass spectrometry, nuclear magnetic resonance, UV-vis, and measured and calculated electronic circular dichroism spectroscopy.
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Weiland KJ, Gallego A, Mayor M. Beyond Simple Substitution Patterns - Symmetrically Tetrasubstituted [2.2]Paracyclophanes as 3D Functional Materials. European J Org Chem 2019. [DOI: 10.1002/ejoc.201900061] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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62
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Kolivoška V, Šebera J, Sebechlebská T, Lindner M, Gasior J, Mészáros G, Mayor M, Valášek M, Hromadová M. Probabilistic mapping of single molecule junction configurations as a tool to achieve the desired geometry of asymmetric tripodal molecules. Chem Commun (Camb) 2019; 55:3351-3354. [PMID: 30815643 DOI: 10.1039/c8cc09681c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Four molecules containing identical tripodal anchors and p-oligophenylene molecular wires of increasing length were used to demonstrate tuning of the asymmetric molecular junction to the desired geometry by probabilistic mapping of single molecule junction configurations in a scanning tunnelling microscopy break junction experiment.
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Weiland KJ, Brandl T, Atz K, Prescimone A, Häussinger D, Šolomek T, Mayor M. Mechanical Stabilization of Helical Chirality in a Macrocyclic Oligothiophene. J Am Chem Soc 2019; 141:2104-2110. [PMID: 30632363 DOI: 10.1021/jacs.8b11797] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We introduce a design principle to stabilize helically chiral structures from an achiral tetrasubstituted [2.2]paracyclophane by integrating it into a macrocycle. The [2.2]paracyclophane introduces a three-dimensional perturbation into a nearly planar macrocyclic oligothiophene. The resulting helical structure is stabilized by two bulky substituents installed on the [2.2]paracyclophane unit. The increased enantiomerization barrier enabled the separation of both enantiomers. The synthesis of the target helical macrocycle 1 involves a sequence of halogenation and cross-coupling steps and a high-dilution strategy to close the macrocycle. Substituents tuning the energy of the enantiomerization process can be introduced in the last steps of the synthesis. The chiral target compound 1 was fully characterized by NMR spectroscopy and mass spectrometry. The absolute configurations of the isolated enantiomers were assigned by comparing the data of circular dichroism spectroscopy with TD-DFT calculations. The enantiomerization dynamics was studied by dynamic HPLC and variable-temperature 2D exchange spectroscopy and supported by quantum-chemical calculations.
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Schätti J, Kriegleder M, Debiossac M, Kerschbaum M, Geyer P, Mayor M, Arndt M, Köhler V. Neutralization of insulin by photocleavage under high vacuum. Chem Commun (Camb) 2019; 55:12507-12510. [DOI: 10.1039/c9cc05712a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Electrosprayed peptide ion beams are charge manipulated by photocleavage of chemical tags.
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Weiland KJ, Münch N, Gschwind W, Häussinger D, Mayor M. A Chiral Macrocyclic Oligothiophene with Broken Conjugation – Rapid Racemization through Internal Rotation. Helv Chim Acta 2018. [DOI: 10.1002/hlca.201800205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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66
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Aeschi Y, Drayss‐Orth S, Valášek M, Häussinger D, Mayor M. Aqueous Assembly of Zwitterionic Daisy Chains. Chemistry 2018; 25:285-295. [DOI: 10.1002/chem.201803944] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Indexed: 12/19/2022]
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67
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Galanti A, Diez-Cabanes V, Santoro J, Valášek M, Minoia A, Mayor M, Cornil J, Samorì P. Electronic Decoupling in C3-Symmetrical Light-Responsive Tris(Azobenzene) Scaffolds: Self-Assembly and Multiphotochromism. J Am Chem Soc 2018; 140:16062-16070. [DOI: 10.1021/jacs.8b06324] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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68
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Stefani D, Weiland KJ, Skripnik M, Hsu C, Perrin ML, Mayor M, Pauly F, van der Zant HSJ. Large Conductance Variations in a Mechanosensitive Single-Molecule Junction. NANO LETTERS 2018; 18:5981-5988. [PMID: 30134105 PMCID: PMC6143316 DOI: 10.1021/acs.nanolett.8b02810] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
An appealing feature of molecular electronics is the possibility of inducing changes in the orbital structure through external stimuli. This can provide functionality on the single-molecule level that can be employed for sensing or switching purposes if the associated conductance changes are sizable upon application of the stimuli. Here, we show that the room-temperature conductance of a spring-like molecule can be mechanically controlled up to an order of magnitude by compressing or elongating it. Quantum-chemistry calculations indicate that the large conductance variations are the result of destructive quantum interference effects between the frontier orbitals that can be lifted by applying either compressive or tensile strain to the molecule. When periodically modulating the electrode separation, a conductance modulation at double the driving frequency is observed, providing a direct proof for the presence of quantum interference. Furthermore, oscillations in the conductance occur when the stress built up in the molecule is high enough to allow the anchoring groups to move along the surface in a stick-slip-like fashion. The mechanical control of quantum interference effects results in the largest-gauge factor reported for single-molecule devices up to now, which may open the door for applications in, e.g., a nanoscale mechanosensitive sensing device that is functional at room temperature.
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69
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Mannancherry R, Rickhaus M, Häussinger D, Prescimone A, Mayor M. Molecular dynamic staircases: all-carbon axial chiral "Geländer" structures. Chem Sci 2018; 9:5758-5766. [PMID: 30079185 PMCID: PMC6050599 DOI: 10.1039/c8sc01707g] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2018] [Accepted: 05/31/2018] [Indexed: 12/02/2022] Open
Abstract
Herein, the syntheses of two tightly packed all-carbon "Geländer" molecules with axial chirality are described. Motivated by our previous results, we further reduced the bridge length by excluding the heteroatoms. The absolute configuration was determined by comparison of the measured and calculated circular dichroism (CD) spectra and the thermodynamic stability was determined by dynamic high-performance liquid chromatography (HPLC) and CD analysis. The cyclophanes were fully characterized by CD measurements, X-ray diffraction (XRD) analysis, NMR, UV-Vis and high resolution mass spectrometry (HRMS). Our novel all-carbon macrocycle is the most stable Geländer system reported so far.
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Bannwart LM, Jundt L, Müntener T, Neuburger M, Häussinger D, Mayor M. Front Cover: A Phenyl-Ethynyl-Macrocycle: A Model Compound for “Geländer” Oligomers Comprising Reactive Conjugated Banisters (Eur. J. Org. Chem. 26/2018). European J Org Chem 2018. [DOI: 10.1002/ejoc.201800997] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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71
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Puebla-Hellmann G, Venkatesan K, Mayor M, Lörtscher E. Metallic nanoparticle contacts for high-yield, ambient-stable molecular-monolayer devices. Nature 2018; 559:232-235. [DOI: 10.1038/s41586-018-0275-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 05/04/2018] [Indexed: 11/09/2022]
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72
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Bannwart LM, Jundt L, Müntener T, Neuburger M, Häussinger D, Mayor M. A Phenyl-Ethynyl-Macrocycle: A Model Compound for “Geländer” Oligomers Comprising Reactive Conjugated Banisters. European J Org Chem 2018. [DOI: 10.1002/ejoc.201800586] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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73
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Debiossac M, Schätti J, Kriegleder M, Geyer P, Shayeghi A, Mayor M, Arndt M, Köhler V. Tailored photocleavable peptides: fragmentation and neutralization pathways in high vacuum. Phys Chem Chem Phys 2018; 20:11412-11417. [PMID: 29645042 PMCID: PMC5932999 DOI: 10.1039/c8cp01058g] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 03/23/2018] [Indexed: 01/31/2023]
Abstract
Photocleavable tags (PCTs) have the potential for excellent spatio-temporal control over the release of subunits of complex molecules. Here, we show that electrosprayed oligopeptides, functionalized by a tailored ortho-nitroarylether can undergo site-specific photo-activated cleavage under UV irradiation (266 nm) in high vacuum. The comparison of UV photodissociation (UVPD) and collision-induced dissociation (CID) points to the thermal nature of the cleavage mechanism, a picture corroborated by the temperature dependence of the process. Two competing photodissociation pathways can be identified. In one case a phenolate anion is separated from a neutral zwitterion. In the other case a neutral phenol derivative leaves a negatively charged peptide behind. To understand the factors favoring one channel over the other, we investigate the influence of the peptide length, the nature of the phenolic group and the position of the nitro-group (ortho vs. para). The observed gas phase cleavage of a para-nitro benzylic ether markedly differs from the established behavior in solution.
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Brandl T, Hoffmann V, Pannwitz A, Häussinger D, Neuburger M, Fuhr O, Bernhard S, Wenger OS, Mayor M. Chiral macrocyclic terpyridine complexes. Chem Sci 2018; 9:3837-3843. [PMID: 29780516 PMCID: PMC5941204 DOI: 10.1039/c7sc05285e] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 03/22/2018] [Indexed: 11/21/2022] Open
Abstract
Interlinking of two terpyridine ligands results in mononuclear chiral metal complexes (Fe and Ru) which were separated into their enantiomers.
The syntheses of novel chiral M(ii) bis(terpyridine) cage complexes Fe(L1)2-c and Ru(L1)2-c are described. The extraordinary design of the precursors Fe(L1)2 and Ru(L1)2 allows perfect preorganization for the final closing step. Due to the rigidity of the spacers between the two terpyridine moieties, the two isolated enantiomers barely racemize at room temperature in solution. The stable and axially chiral bis(terpyridine) Fe(ii) and Ru(ii) complexes were fully characterized by NMR-spectroscopy, UV-Vis spectroscopy, electrochemical measurements, high resolution mass spectrometry, circular dichroism measurements, and X-ray structural analysis.
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75
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Bi H, Palma CA, Gong Y, Hasch P, Elbing M, Mayor M, Reichert J, Barth JV. Voltage-Driven Conformational Switching with Distinct Raman Signature in a Single-Molecule Junction. J Am Chem Soc 2018; 140:4835-4840. [DOI: 10.1021/jacs.7b12818] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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