1
|
Stähler C, Reynaerts R, Rinkovec T, Verstraete L, Heideman GH, Minoia A, Harvey JN, Mali KS, De Feyter S, Feringa BL. Highly Ordered Co-Assembly of Bisurea Functionalized Molecular Switches at the Solid-Liquid Interface. Chemistry 2024:e202303994. [PMID: 38323675 DOI: 10.1002/chem.202303994] [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: 11/30/2023] [Indexed: 02/08/2024]
Abstract
Immobilization of stimulus-responsive systems on solid surfaces is beneficial for controlled signal transmission and adaptive behavior while allowing the characterization of the functional interface with high sensitivity and high spatial resolution. Positioning of the stimuli-responsive units with nanometer-scale precision across the adaptive surface remains one of the bottlenecks in the extraction of cooperative function. Nanoscale organization, cooperativity, and amplification remain key challenges in bridging the molecular and the macroscopic worlds. Here we report on the design, synthesis, and scanning tunneling microscopy (STM) characterization of overcrowded alkene photoswitches merged in self-assembled networks physisorbed at the solid-liquid interface. A detailed anchoring strategy that ensures appropriate orientation of the switches with respect to the solid surface through the use of bis-urea groups is presented. We implement a co-assembly strategy that enables the merging of the photoswitches within physisorbed monolayers of structurally similar 'spacer' molecules. The self-assembly of the individual components and the co-assemblies was examined in detail using (sub)molecular resolution STM which confirms the robust immobilization and controlled orientation of the photoswitches within the spacer monolayers. The experimental STM data is supported by detailed molecular mechanics (MM) simulations. Different designs of the switches and the spacers were investigated which allowed us to formulate guidelines that enable the precise organization of the photoswitches in crystalline physisorbed self-assembled molecular networks.
Collapse
Affiliation(s)
- Cosima Stähler
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Robby Reynaerts
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Tamara Rinkovec
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Lander Verstraete
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
- imec, Kapeldreef 75, 3001, Leuven, Belgium
| | - G Henrieke Heideman
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Andrea Minoia
- Laboratory for Chemistry of Novel Materials, Materials Research Institute, University of Mons, Place du Parc 20, 7000, Mons, Belgium
| | - Jeremy N Harvey
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Kunal S Mali
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Steven De Feyter
- Division of Molecular Imaging and Photonics, Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001, Leuven, Belgium
| | - Ben L Feringa
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| |
Collapse
|
2
|
Kawai S, Sugawara K, Ma Y, Sun K, Custance O, Ishigaki Y, Suzuki T. Multiple Molecular Interactions between Alkyl Groups and Dissociated Bromine Atoms on Ag(111). Phys Chem Chem Phys 2022; 24:22191-22197. [DOI: 10.1039/d2cp03198a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Multiple intermolecular interactions offer a high-degree of controllability of on-surface molecular assemblies. Here, two kinds of molecular networks were formed by depositing 11,11,12,12-tetrabromo-1,4,5,8-tetraaza-9,10-anthraquinodimethane derivatives with two different alkyl groups in...
Collapse
|
3
|
Sato YU, Sano M. Dispersing single-walled carbon nanotubes using common phospholipids with a small amount of polyethylene glycol-phospholipid additives. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2013.09.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
4
|
Sacchi M, Brewer AY, Jenkins SJ, Parker JE, Friščić T, Clarke SM. Combined diffraction and density functional theory calculations of halogen-bonded cocrystal monolayers. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:14903-14911. [PMID: 24215390 PMCID: PMC3968856 DOI: 10.1021/la402910a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 10/31/2013] [Indexed: 05/31/2023]
Abstract
This work describes the combined use of synchrotron X-ray diffraction and density functional theory (DFT) calculations to understand the cocrystal formation or phase separation in 2D monolayers capable of halogen bonding. The solid monolayer structure of 1,4-diiodobenzene (DIB) has been determined by X-ray synchrotron diffraction. The mixing behavior of DIB with 4,4'-bipyridyl (BPY) has also been studied and interestingly is found to phase-separate rather than form a cocrystal, as observed in the bulk. DFT calculations are used to establish the underlying origin of this interesting behavior. The DFT calculations are demonstrated to agree well with the recently proposed monolayer structure for the cocrystal of BPY and 1,4-diiodotetrafluorobenzene (DITFB) (the perfluorinated analogue of DIB), where halogen bonding has also been identified by diffraction. Here we have calculated an estimate of the halogen bond strength by DFT calculations for the DITFB/BPY cocrystal monolayer, which is found to be ∼20 kJ/mol. Computationally, we find that the nonfluorinated DIB and BPY are not expected to form a halogen-bonded cocrystal in a 2D layer; for this pair of species, phase separation of the components is calculated to be lower energy, in good agreement with the diffraction results.
Collapse
Affiliation(s)
- Marco Sacchi
- Department of Chemistry and Department of Chemistry and BP Institute, Cambridge University, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Adam Y. Brewer
- Department of Chemistry and Department of Chemistry and BP Institute, Cambridge University, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Stephen J. Jenkins
- Department of Chemistry and Department of Chemistry and BP Institute, Cambridge University, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Julia E. Parker
- Diamond Light
Source, Harwell Science and Innovation Campus, Didcot, Oxon, United Kingdom
| | - Tomislav Friščić
- Department of Chemistry and Department of Chemistry and BP Institute, Cambridge University, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| | - Stuart M. Clarke
- Department of Chemistry and Department of Chemistry and BP Institute, Cambridge University, Lensfield Road, Cambridge CB2 1EW, United Kingdom
| |
Collapse
|
5
|
|
6
|
Makoudi Y, Baris B, Jeannoutot J, Palmino F, Grandidier B, Cherioux F. Tailored Molecular Design for Supramolecular Network Engineering on a Silicon Surface. Chemphyschem 2013; 14:900-4. [DOI: 10.1002/cphc.201200822] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 01/12/2013] [Indexed: 11/10/2022]
|
7
|
Silly F. Moiré pattern induced by the electronic coupling between 1-octanol self-assembled monolayers and graphite surface. NANOTECHNOLOGY 2012; 23:225603. [PMID: 22572595 DOI: 10.1088/0957-4484/23/22/225603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Two-dimensional self-assembly of 1-octanol molecules on a graphite surface is investigated using scanning tunneling microscopy (STM) at the solid/liquid interface. STM images reveal that this molecule self-assembles into a compact hydrogen-bonded herringbone nanoarchitecture. Molecules are preferentially arranged in a head-to-head and tail-to-tail fashion. A Moiré pattern appears in the STM images when the 1-octanol layer is covering the graphite surface. The large Moiré stripes are perpendicular to the 1-octanol lamellae. Interpretation of the STM images suggests that the Moiré periodicity is governed by the electronic properties of the graphite surface and the 1-octanol layer periodicity.
Collapse
Affiliation(s)
- Fabien Silly
- CEA, IRAMIS, SPCSI, Hybrid Magnetic Nanoarchitectures, F-91191 Gif sur Yvette, France
| |
Collapse
|
8
|
Sun C, Clarke S, Brewer A, Li B, Parker J, Demmel F. The structures of 1-bromoheptane and 1-bromononane monolayers adsorbed on the surface of graphite. Mol Phys 2012. [DOI: 10.1080/00268976.2011.640290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
9
|
Leung L, Lim T, Polanyi JC, Hofer WA. Molecular calipers control atomic separation at a metal surface. NANO LETTERS 2011; 11:4113-4117. [PMID: 21905693 DOI: 10.1021/nl2023788] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
If a molecule controls the length of some other moiety, it can be termed a "molecular caliper". Here we image individual molecular calipers of this type by scanning tunneling microscopy. These consist of linear polymers of p-diiodobenzene, (pDIB)n, of varying length, 0.7-2.9 nm, physisorbed on Cu(110) at 4.6 K. Through electron-induced reaction these chemically imprint their terminal I-atoms on the copper, 0.7 nm further apart than their initial separations. The physisorbed monomer or polymer, therefore, constitutes a molecular-caliper with variable terminal I..I separation. The localized nature of the I-atom reaction at the copper surface relative to the parent molecule, constitutes a novel finding reported here. It ensures that the separation of the I-atoms in the physisorbed molecular caliper correlates with their subsequent separation when chemisorbed at the surface.
Collapse
Affiliation(s)
- Lydie Leung
- Lash Miller Chemical Laboratories, Department of Chemistry and Institute of Optical Science, University of Toronto , 80 St. George Street, Ontario, M5S 3H6, Canada
| | | | | | | |
Collapse
|
10
|
Lackinger M, Heckl WM. Carboxylic acids: versatile building blocks and mediators for two-dimensional supramolecular self-assembly. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11307-21. [PMID: 19453128 DOI: 10.1021/la900785f] [Citation(s) in RCA: 136] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Two-dimensional (2D) supramolecular self-assembly of various organic molecules at the liquid-solid interface is presented and discussed with a focus on compounds that are primarily functionalized by carboxylic groups. The main analytical tool utilized is scanning tunneling microscopy (STM), a high-resolution real-space technique capable of readily providing full crystallographic information (i.e., not only lattice parameters but also number, type, and orientation of molecules within the unit cell). Carboxylic groups are of particular interest because their combined donor and acceptor character with regard to hydrogen bonds provides reliable intermolecular cross-linking, thereby facilitating the self-assembly of well-ordered, stable monolayers. By means of various homomeric (monomolecular) and heteromeric (here, bimolecular) examples, this feature article illustrates the influence of both molecular structure and external conditions (type of solvent, concentration, etc.) on monolayer self-assembly at the liquid-solid interface. A very intriguing aspect of interfacial self-assembly is that many systems are thermodynamically controlled (i.e., adsorbed molecules at the surface are in equilibrium with molecules dissolved in the supernatant liquid phase). This offers the unique possibility not only to steer the system reliably by intensive thermodynamic parameters such as temperature and concentration but also to gain fundamental knowledge about decisive processes and steps in supramolecular self-assembly.
Collapse
Affiliation(s)
- Markus Lackinger
- Ludwig-Maximilians-University and Center for NanoScience (CeNS), Department for Earth and Environmental Sciences, Theresienstrasse 41, DE-80333 München, Germany.
| | | |
Collapse
|
11
|
Kwon KY, Pawin G, Wong KL, Peters E, Kim D, Hong S, Rahman TS, Marsella M, Bartels L. H-Atom Position as Pattern-Determining Factor in Arenethiol Films. J Am Chem Soc 2009; 131:5540-5. [DOI: 10.1021/ja809417k] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ki-Young Kwon
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Greg Pawin
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Kin L. Wong
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Eric Peters
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Daeho Kim
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Sampyo Hong
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Talat S. Rahman
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Michael Marsella
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| | - Ludwig Bartels
- Pierce Hall/Department of Chemistry, University of California−Riverside, Riverside, California 92521, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Departments of Chemistry/Electrical Engineering, University of California−Los Angeles, Los Angeles, California 90095, and Department of Physics, University of Central Florida, Orlando, Florida 32816
| |
Collapse
|
12
|
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.
Collapse
Affiliation(s)
- Jingdong Zhang
- Department of Chemistry, NanoDTU, Building 207, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark.
| | | | | | | | | |
Collapse
|
13
|
Ilan B, Florio GM, Hybertsen MS, Berne BJ, Flynn GW. Scanning tunneling microscopy images of alkane derivatives on graphite: role of electronic effects. NANO LETTERS 2008; 8:3160-3165. [PMID: 18798685 DOI: 10.1021/nl8014186] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Scanning tunneling microscopy (STM) images of self-assembled monolayers of close-packed alkane chains on highly oriented pyrolitic graphite often display an alternating bright and dark spot pattern. Classical simulations suggest that a tilt of the alkane backbone is unstable and, therefore, unlikely to account for the contrast variation. First principles calculations based on density functional theory show that an electronic effect can explain the observed alternation. Furthermore, the asymmetric spot pattern associated with the minimum energy alignment is modulated depending on the registry of the alkane adsorbate relative to the graphite surface, explaining the characteristic moiré pattern that is often observed in STM images with close packed alkyl assemblies.
Collapse
Affiliation(s)
- Boaz Ilan
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | | | | | | | | |
Collapse
|
14
|
Yang T, Berber S, Liu JF, Miller GP, Tománek D. Self-assembly of long chain alkanes and their derivatives on graphite. J Chem Phys 2008; 128:124709. [PMID: 18376962 DOI: 10.1063/1.2841478] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Teng Yang
- Physics and Astronomy Department, Michigan State University, East Lansing, Michigan 48824-2320, USA
| | | | | | | | | |
Collapse
|
15
|
Rim KT, Siaj M, Xiao S, Myers M, Carpentier VD, Liu L, Su C, Steigerwald ML, Hybertsen MS, McBreen PH, Flynn GW, Nuckolls C. Forming Aromatic Hemispheres on Transition-Metal Surfaces. Angew Chem Int Ed Engl 2007; 46:7891-5. [PMID: 17879251 DOI: 10.1002/anie.200701117] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Kwang Taeg Rim
- Department of Chemistry and The Center for Electron Transport in Molecular Nanostructures, Columbia University, New York, NY 10027, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Rim K, Siaj M, Xiao S, Myers M, Carpentier V, Liu L, Su C, Steigerwald M, Hybertsen M, McBreen P, Flynn G, Nuckolls C. Forming Aromatic Hemispheres on Transition-Metal Surfaces. Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200701117] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
17
|
Kannappan K, Werblowsky TL, Rim KT, Berne BJ, Flynn GW. An Experimental and Theoretical Study of the Formation of Nanostructures of Self-Assembled Cyanuric Acid through Hydrogen Bond Networks on Graphite. J Phys Chem B 2007; 111:6634-42. [PMID: 17455975 DOI: 10.1021/jp0706984] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The self-assembly of cyanuric acid into ordered nanostructures on a crystalline substrate, highly ordered pyrolytic graphite (HOPG), has been investigated at low temperature under ultrahigh vacuum (UHV) conditions by means of scanning tunneling microscopy in conjunction with theoretical simulations. Many domains with different self-assembly patterns were observed. One such domain represents the formation of an open 2D rosette (cyclic) structure from the self-assembly process, the first observation of this type of structure for pure cyanuric acid on a graphite substrate. Each self-assembled domain exhibits characteristic superstructures formed through different hydrogen bond networks at low coverage and low deposition rate. Experimental observation of coexistent, two-dimensional crystalline structures with distinct hydrogen bond patterns is supported by energy minimizations and molecular dynamics calculations, which show multiple stable structures for this molecule when self-assembled on graphite.
Collapse
Affiliation(s)
- Kavita Kannappan
- Department of Chemistry and Nanoscale Science and Engineering Center (NSEC), Columbia University, New York, New York 10027, USA
| | | | | | | | | |
Collapse
|
18
|
Shao X, Luo X, Hu X, Wu K. Chain-Length Effects on Molecular Conformation in and Chirality of Self-Assembled Monolayers of Alkoxylated Benzo[c]cinnoline Derivatives on Highly Oriented Pyrolytic Graphite. J Phys Chem B 2006; 110:15393-402. [PMID: 16884260 DOI: 10.1021/jp060811a] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Self-assembled structures of alkoxylated benzo[c]cinnoline derivatives prepared on highly oriented pyrolytic graphite at room temperature from their solutions in solvents such as 1-phenyloctane, toluene, and 1-octanol were studied by scanning tunneling microscopy. The alkoxy chain length markedly affected the molecular conformations in 2-dimensional assemblies of these derivatives. Long-chain derivatives adopted the trans conformations more often than cis, whereas short-chain derivatives took exclusively the cis conformations in the self-assembled monolayers (SAMs). For the derivatives of intermediate chain lengths, polymorphism existed, with four molecular conformations identified experimentally. Experimental evidence substantiated the formation of chiral SAM structures at the surface, which can be explained by the conformations of the molecules. The chirality was also affected by the chain length of the molecules. A simple method analyzing the angles between different domains in the SAMs was used to identify the molecular conformations and to predict their relative structures.
Collapse
Affiliation(s)
- Xiang Shao
- State Key Laboratory for Structural Chemistry of Stable and Unstable Species, Institute of Physical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | | | | | | |
Collapse
|
19
|
Dobrin S, Harikumar KR, Polanyi JC. STM Study of the Conformation and Reaction of Long-Chain Haloalkanes at Si(111)-7 × 7. J Phys Chem B 2006; 110:8010-8. [PMID: 16610901 DOI: 10.1021/jp0573339] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Scanning tunneling microscopy (STM) has been used to study the adsorption of 1-fluoro-, 1-chloro-, and 1-bromo-substituted C(12) alkanes at the Si(111)-7 x 7 surface, at temperatures from 300 to 500 K. We report self-assembly of these physisorbed adsorbates, C(12)H(25)X, to form approximately circular corrals, (C(12)H(25)X)(2), with charge transfer to a corralled adatom in each case (cf. Dobrin et al. Surf. Sci. 2006, 600, L43). The corrals comprised pairs of semicircular horizontal long-chain molecules stable to approximately 100 degrees C. At > or =150 degrees C, the corrals desorbed or reacted locally to imprint a halogen atom, X-Si, and an adjacent alkane residue, R-Si. The corral height profiles, together with the location of the imprinted X-Si resulting from thermal or electron-induced surface reaction, led to a picture of the molecular configurations in these haloalkane corrals, (C(12)H(25)X)(2), X = F, Cl, Br, and the dichloro corrals, 1,12-dichlorododecane, (ClC(12)H(24)Cl)(2).
Collapse
Affiliation(s)
- Sergey Dobrin
- Lash Miller Chemical Laboratories, Department of Chemistry and Institute of Optical Sciences, University of Toronto, 80 St. George Street, Ontario M5S 3H6, Canada
| | | | | |
Collapse
|
20
|
|