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Roth C, Passerone D, Ernst KH. Pasteur's quasiracemates in 2D: chiral conflict between structurally different enantiomers induces single-handed enantiomorphism. Chem Commun (Camb) 2010; 46:8645-7. [DOI: 10.1039/c0cc03060k] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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53
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Zhang J, Lu T, Jiang C, Zou J, Cao F, Chen Y. Mechanisms for chemical transformations of (R,R)-tartaric acid on Cu(110): A first principles study. J Chem Phys 2009; 131:144703. [DOI: 10.1063/1.3247188] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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Abstract
Abstract
Phenomena like transfer, expression and amplification of chirality in molecular monolayers are reviewed. Chirality can be bestowed onto achiral surfaces by adsorption of chiral molecules. This offers a good opportunity to study two-dimensional chiral crystallization phenomena, like lateral resolution of enantiomers or the transfer of handedness from single molecules into mesoscopic ensembles at high resolution with scanning probe microscopy. Induction of homochirality on surfaces via cooperatively amplified interactions in molecular monolayers is a new phenomenon of supramolecular surface chirality. Prochiral molecules will turn into either handedness upon adsorption, but doping with intrinsically chiral molecules breaks this symmetry and induces homochirality. A similar effect is induced by a small enantiomeric excess. The excess molecules provide the chiral bias that becomes amplified into single lattice chirality.
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55
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Elemans J, Lei S, De Feyter S. Molekulare und supramolekulare Netzwerke auf Oberflächen: vom zweidimensionalen Kristall-Engineering bis zur Reaktivität. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200806339] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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56
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Elemans J, Lei S, De Feyter S. Molecular and Supramolecular Networks on Surfaces: From Two-Dimensional Crystal Engineering to Reactivity. Angew Chem Int Ed Engl 2009; 48:7298-332. [DOI: 10.1002/anie.200806339] [Citation(s) in RCA: 576] [Impact Index Per Article: 38.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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57
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Baddeley CJ. Giving surfaces a hand. Nat Chem 2009; 1:345-6. [DOI: 10.1038/nchem.307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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58
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Zhang J, Chi Q, Nazmutdinov RR, Zinkicheva TT, Bronshtein MD. Submolecular electronic mapping of single cysteine molecules by in situ scanning tunneling imaging. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:2232-2240. [PMID: 19161269 DOI: 10.1021/la8034006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have used L-cysteine (Cys) as a model system to study the surface electronic structures of single molecules at the submolecular level in aqueous buffer solution by a combination of electrochemical scanning tunneling microscopy (in situ STM), electrochemistry including voltammetry and chronocoulometry, and density functional theory (DFT) computations. Cys molecules were assembled on single-crystal Au(110) surfaces to form a highly ordered monolayer with a periodic lattice structure of c(2x2) in which each unit contains two molecules; this conclusion is confirmed by the results of calculations based on a slab model for the metal surface. The ordered monolayer offers a platform for submolecular scale electronic mapping that is an issue of fundamental interest but remains a challenge in STM imaging science and surface chemistry. Single Cys molecules were mapped as three electronic subunits contributed mainly from three chemical moieties: thiol (-SH), carboxylic (-COOH), and amine (-NH2) groups. The contrasts of the three subunits depend on the environment (e.g., pH), which affects the electronic structure of adsorbed species. From the DFT computations focused on single molecules, rational analysis of the electronic structures is achieved to delineate the main factors that determine electronic contrasts in the STM images. These factors include the molecular orientation, the chemical nature of the elements or groups in the molecule, and the interaction of the elements with the substrate and tip. The computational images recast as constant-current-height profiles show that the most favorable molecular orientation is the adsorption of cysteine as a radical in zwitterionic form located on the bridge between the Au(110) atomic rows and with the amine and carboxyl group toward the solution bulk. The correlation between physical location and electronic contrast of the adsorbed molecules was also revealed by the computational data. The present study shows that cysteine packing in the adlayer on Au(110) from the liquid environment is in contrast to that from the ultrahigh-vacuum environment, suggesting solvent plays a role during molecular assembly.
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Affiliation(s)
- Jingdong Zhang
- Department of Chemistry, NanoDTU, Building 207, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
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59
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Jones G, Jenkins SJ. Insight into the Reduction of Pyruvic Acid to Lactic Acid over Cu{110}: The Crucial Role of Intramolecular Tunneling in Direct Hydrogenation. J Am Chem Soc 2008; 130:14483-92. [DOI: 10.1021/ja077786m] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Glenn Jones
- The University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge, CB2 1EW, U.K
| | - Stephen J. Jenkins
- The University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge, CB2 1EW, U.K
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60
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Mallat T, Orglmeister E, Baiker A. Asymmetric Catalysis at Chiral Metal Surfaces. Chem Rev 2007; 107:4863-90. [DOI: 10.1021/cr0683663] [Citation(s) in RCA: 501] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- T. Mallat
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Hönggerberg, CH-8093 Zurich, Switzerland
| | - E. Orglmeister
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Hönggerberg, CH-8093 Zurich, Switzerland
| | - A. Baiker
- Institute for Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zurich, Hönggerberg, CH-8093 Zurich, Switzerland
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61
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Liu N, Haq S, Darling GR, Raval R. Direct Visualization of Enantiospecific Substitution of Chiral Guest Molecules into Heterochiral Molecular Assemblies at Surfaces. Angew Chem Int Ed Engl 2007; 46:7613-6. [PMID: 17712805 DOI: 10.1002/anie.200701675] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ning Liu
- Surface Science Research Centre, Department of Chemistry, The University of Liverpool, Liverpool, UK
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62
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Liu N, Haq S, Darling G, Raval R. Direct Visualization of Enantiospecific Substitution of Chiral Guest Molecules into Heterochiral Molecular Assemblies at Surfaces. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200701675] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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63
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Pérez-García L, Amabilino DB. Spontaneous resolution, whence and whither: from enantiomorphic solids to chiral liquid crystals, monolayers and macro- and supra-molecular polymers and assemblies. Chem Soc Rev 2007; 36:941-67. [PMID: 17534480 DOI: 10.1039/b610714a] [Citation(s) in RCA: 339] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
One of the great challenges in stereochemistry is the explanation of why some molecules resolve spontaneously while others do not. In this critical review the recent advances in the creation of chiral systems from achiral and racemic compounds in three-, two- and one-dimensional systems are discussed. There are some groups of molecules in some systems that do tend to display conglomerates, which may suggest that there are enantiophobic and enantiophilic molecules whose assembly is guided by the structural and thermodynamic properties of the systems in question.
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Affiliation(s)
- Lluïsa Pérez-García
- Laboratori de Química Orgànica, Facultat de Farmàcia, and Institut de Nanociència i Nanotecnologia, Universitat de Barcelona, 08028, Barcelona, Spain. mlperez@ ub.edu
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64
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Dmitriev A, Spillmann H, Stepanow S, Strunskus T, Wöll C, Seitsonen AP, Lingenfelder M, Lin N, Barth JV, Kern K. Asymmetry Induction by Cooperative Intermolecular Hydrogen Bonds in Surface-Anchored Layers of Achiral Molecules. Chemphyschem 2006; 7:2197-204. [PMID: 16955528 DOI: 10.1002/cphc.200600110] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The mesoscale induction of two-dimensional supramolecular chirality (formation of 2D organic domains with a single handedness) was achieved by self-assembly of 1,2,4-benzenetricarboxylic (trimellitic) acid on a Cu(100) surface at elevated temperatures. The combination of spectroscopic [X-ray photoelectron spectroscopy (XPS) and near-edge X-ray absorption fine structure (NEXAFS)], real-space-probe [scanning tunneling microscopy (STM)], and computational [density functional theory (DFT)] methods allows a comprehensive characterization of the obtained organic adlayers, where details of molecular adsorption geometry, intermolecular coupling, and surface chemical bonding are elucidated. The trimellitic acid species, comprising three functional carboxylic groups, form distinct stable mirror-symmetric hydrogen-bonded domains. The chiral ordering is associated with conformational restriction in the domains: molecules anchor to the substrate with an ortho carboxylate group, providing two para carboxylic acid moieties for collective lateral interweaving through H bonding, which induces a specific tilt of the molecular plane. The ease of molecular symmetry switching in domain formation makes homochiral-signature propagation solely limited by the terrace width. The molecular layer modifies the morphology of the underlying copper substrate and induces mum-sized strictly homochiral terraces.
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65
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66
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Jones TE, Baddeley CJ. Investigating the mechanism of chiral surface reactions: the interaction of methylacetoacetate with (S)-glutamic Acid modified Ni{111}. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2006; 22:148-52. [PMID: 16378413 DOI: 10.1021/la0521239] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The enantioselective hydrogenation of beta ketoesters over Ni-based catalysts is a rare example of a heterogeneously catalyzed chiral reaction. The key step in catalyst preparation is the adsorption from solution of chiral molecules (modifiers). One particularly interesting modifier is (S)-glutamic acid because the dominant enantiomeric product in the catalytic reaction depends upon the modification temperature. We report a reflection absorption infrared spectroscopy (RAIRS) study of the adsorption of methylacetoacetate (the simplest beta ketoester) onto (S)-glutamic acid modified Ni{111} surfaces as functions of the modifier coverage and modification temperature. We show that the sticking probability of methylacetoacetate is close to 0 on saturated (S)-glutamic acid covered surfaces. At lower modifier coverage, methylacetoacetate adsorption can occur. Adsorption of methylacetoacetate onto a Ni{111} surface modified by (S)-glutamic acid at 300 K results in the diketo tautomeric form, with evidence being observed for a 1:1 interaction between zwitterionic (S)-glutamate and methylacetoacetate. In contrast, adsorption of methylacetoacetate onto a Ni{111} surface modified by (S)-glutamic acid at 350 K occurs exclusively in the enol tautomeric form. The implications for the heterogeneous catalytic reaction are discussed.
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Affiliation(s)
- T E Jones
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife KY169ST, UK
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67
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Mulligan A, Lane I, Rousseau GBD, Johnston SM, Lennon D, Kadodwala M. Lifting the Mirror Symmetry of Metal Surfaces: Decoupling the Electronic and Physical Manifestations of Surface Chirality. J Phys Chem B 2006; 110:1083-90. [PMID: 16471645 DOI: 10.1021/jp055518+] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Naturally occurring metal surfaces possess planes of mirror symmetry on the nanometer-length scale. This mirror symmetry can be lifted and chirality "physically" conveyed onto a surface by adsorbing a chiral molecule. Until now, it has not been known whether the conveying of chirality is limited to just the physical structure or whether it goes deeper and permeates the electronic structure of the underlying surface. By using optically active second harmonic generation (OA-SHG), it is demonstrated that the adsorption of some, but not all, chiral molecules can reversibly, and without significant structural rearrangement, measurably lift the mirror symmetry of the surface electronic structure of a metal. It is proposed that the ability of a chiral molecule to place a significant "chiral perturbation" on the electronic structure of a surface is correlated to its adsorption geometry. The microscopic origins of the observed optical activity are also discussed in terms of classical models of chirality. The results of the study challenge current models of how chiral adsorbates induce enantioselectivity in the chemical/physical behavior of heterogeneous systems, which are based on geometric/stereochemical arguments, by suggesting that chiral electronic perturbations could play a role.
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Affiliation(s)
- Andrew Mulligan
- Department of Chemistry, Joseph Black Building, University of Glasgow, Glasgow G12 8QQ, UK
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68
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Stepanow S, Lin N, Barth JV, Kern K. Non-covalent binding of fullerenes and biomolecules at surface-supported metallosupramolecular receptors. Chem Commun (Camb) 2006:2153-5. [PMID: 16703138 DOI: 10.1039/b603003c] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In-situ scanning tunneling microscopy study reveals that two-dimensional metallosupramolecular receptors bind a single or a discrete number of cystine, C60, or diphenylalanine molecules reversibly through non-covalent interactions.
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Affiliation(s)
- Sebastian Stepanow
- Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569, Stuttgart, Germany
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69
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Xu B, Tao C, Cullen WG, Reutt-Robey JE, Williams ED. Chiral symmetry breaking in two-dimensional C60-ACA intermixed systems. NANO LETTERS 2005; 5:2207-11. [PMID: 16277454 DOI: 10.1021/nl051415r] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We have demonstrated a method for fabricating C60 overlayers with controlled spacing and chirality by reactive coadsorption with the aromatic molecule acridine-9-carboxylic acid (ACA). Structural control is achieved by the mismatched symmetries of the coadsorbates, as well as specific intermolecular and adsorbate-substrate interactions. The resulting supramolecular structure has a C60 period nearly three times as large as the normal C60 2D packing of 1 nm and exists in enantiopure domains with robust chirality.
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Affiliation(s)
- Bo Xu
- Department of Chemistry, University of Maryland, College Park, Maryland 20742, USA
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70
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Romer S, Behzadi B, Fasel R, Ernst KH. Homochiral Conglomerates and Racemic Crystals in Two Dimensions: Tartaric Acid on Cu(110). Chemistry 2005; 11:4149-54. [PMID: 15861485 DOI: 10.1002/chem.200400962] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Two-dimensional lattice structures formed by racemic tartaric acid on a single crystalline Cu(110) surface have been studied and compared with the enantiopure lattices. At low coverage, the doubly deprotonated bitartrate species is separated into two-dimensional conglomerates showing opposite enantiomorphism. At higher coverage, however, a singly deprotonated monotartrate species forms a heterochiral, racemic crystal lattice. While the enantioseparated bitartrate system undergoes decomposition at the same temperature as the enantiopure system, the racemic monotartrate lattice has a lower thermal stability than the enantiopure lattice of identical periodicity and surface density. At monolayer saturation coverage, the pure enantiomers form a denser lattice than the racemate. This is in contrast to the three-dimensional tartaric acid crystals, where the racemate crystallizes in a lattice of higher density, which is also more thermally stable than the enantiopure tartaric acid crystals.
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Affiliation(s)
- Sara Romer
- Nanoscale Materials Science, Swiss Federal Institute for Materials Science and Technology (EMPA), Dübendorf, Switzerland
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71
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Parschau M, Romer S, Ernst KH. Induction of Homochirality in Achiral Enantiomorphous Monolayers. J Am Chem Soc 2004; 126:15398-9. [PMID: 15563164 DOI: 10.1021/ja044136z] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report the induction of homochirality in enantiomorphous layers of achiral succinic acid on a Cu(110) surface after doping with tartaric acid (TA) enantiomers. Succinic acid becomes chiral upon adsorption due to symmetry-breaking interactions with the Cu(110) surface. The doubly deprotonated bisuccinate forms mirror domains on the surface, which leads to a superposition of (11,-90) and (90,-11) patterns observed by low-energy electron diffraction (LEED). On average, however, the surface layer is racemic. An amount of 2 mol % of (R,R)- or (S,S)-tartaric acid in the monolayer, corresponding to an absolute coverage of 0.001 tartaric acid molecule per surface copper atom, is sufficient to make the LEED spots of one enantiomorphous lattice disappear. After thermally induced desorption of TA, the succinic acid lattice turns racemic again. In analogy to the "sergeants-and-soldiers" principle described for helical polymers, this effect is explained by a lateral cooperative interaction within the two-dimensional lattice.
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Affiliation(s)
- Manfred Parschau
- Swiss Federal Laboratories for Materials Research (EMPA), Molecular Surface Technologies-125, Uberlandstrasse 129, CH 8600 Dübendorf, Switzerland
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73
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Behzadi B, Romer S, Fasel R, Ernst KH. Chiral Recognition in Surface Explosion. J Am Chem Soc 2004; 126:9176-7. [PMID: 15281795 DOI: 10.1021/ja048206d] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The vast majority of chiral compounds crystallize into racemic crystals. It has been predicted and was experimentally established as a rule that chiral molecules on surfaces are more easily separated into homochiral domains due to confinement into a plane and lower entropic contributions. We investigated the formation and stability of two-dimensional tartrate crystals on a Cu(110) surface for the racemic mixture for the first time by means of temperature-programmed desorption (TPD), low-energy electron diffraction (LEED), and X-ray photoelectron spectroscopy (XPS). At low coverage, a bitartrate species becomes separated into homochiral domains, while at high coverage a monotartrate species forms a racemic mixture. At the same coverage and lateral arrangement, the thermally induced autocatalytic decomposition reaction occurs for the monotartrate racemate at a lower temperature than for the pure enantiomers. The stereochemistry in this so-called "surface explosion" reaction is explained by a higher stability of the enantiopure lattice due to lateral hydrogen-bond formation. The higher stability of the enantiopure two-dimensional lattice is in contrast to the higher stability of racemic three-dimensional tartaric acid crystals but is consistent with the observation that homochirality is preferred in hydrogen-bonded self-assembled biomolecular structures.
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Affiliation(s)
- Bahar Behzadi
- Swiss Federal Laboratories for Materials Research (EMPA), Molecular Surfaces Technologies-125, Uberlandstrasse 129, CH-8600 Dübendorf, Switzerland
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