1
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Xing KY, Bao HH, Ding NS, Xiong YH, Peng J, Lai WH. Two-step aggregation of gold nanoparticles based on charge neutralization for detection of melamine by colorimetric and surface-enhanced Raman spectroscopy platform. J Dairy Sci 2022; 105:7298-7307. [PMID: 35863920 DOI: 10.3168/jds.2022-22037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Accepted: 04/20/2022] [Indexed: 11/19/2022]
Abstract
A colorimetric and surface-enhanced Raman scattering (SERS) signal amplification platform based on 2-step aggregation of gold nanoparticles (AuNP) was constructed for the sensitive detection of melamine. In this study, the positively charged SYBR Green I was used for the first step of aggregation of AuNP, via charge neutralization, to obtain small-sized AuNP aggregates. The positively charged SYBR Green I decreased the negative charges of the surface of AuNP, which was beneficial to the aggregation of AuNP. In addition, the melamine could aggregate AuNP by decreasing the negative charges of the surface of AuNP and self-assemble with each other on the surface of AuNP by hydrogen bonds. Therefore, the second efficient aggregation of small-sized AuNP aggregates could be achieved with melamine at low concentration, resulting in significant signal changes of color and SERS. The sensitivity of a colorimetric (0.60 mg/L) and SERS (0.089 mg/L) platform, based on 2-step aggregation of AuNP, was 15 and 2.2 times higher than that based on 1-step aggregation of AuNP for detecting melamine.
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Affiliation(s)
- K Y Xing
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - H H Bao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - N S Ding
- State Key Laboratory of Food Safety Technology for Meat Products, Xiamen, 361116, China; State Key Laboratory of Pig Genetic Improvement and Production Technology, Jiangxi Agricultural University, Nanchang, 330045, China
| | - Y H Xiong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - J Peng
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China
| | - W H Lai
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang, 330047, China.
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2
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Yoshimoto S, Ogata H. Molecular planting of a single organothiol into a "gap-site" of a 2D patterned adlayer in an electrochemical environment. Chem Sci 2022; 13:4999-5005. [PMID: 35655888 PMCID: PMC9067580 DOI: 10.1039/d1sc07227g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 04/08/2022] [Indexed: 11/21/2022] Open
Abstract
The self-assembled inclusion of molecules into two-dimensional (2D) porous networks on surfaces has been extensively studied because 2D functional materials consisting of organic molecules have become an important research topic. However, the isolation of a single molecular thiol remains a challenging goal. Here, we report a method of planting and isolating organothiols onto a 2D patterned organic adlayer at an electrochemical interface. In situ scanning tunneling microscopy revealed that the phase transition of an ovalene adlayer is electrochemically induced and that the gap site created by three ovalene molecules serves as a 2D molecular template to isolate thiol molecules and to standardize the distance between them via the formation of precise selective open spaces, suggesting that electrochemical "molecular planting" opens applications for 2D patterns of isolated single organothiol molecules.
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Affiliation(s)
- Soichiro Yoshimoto
- Institute of Industrial Nanomaterials, Kumamoto University 2-39-1 Kurokami, Chuo-ku Kumamoto 860-8555 Japan
| | - Hiroto Ogata
- Graduate School of Science and Technology, Kumamoto University 2-39-1 Kurokami, Chuo-ku Kumamoto 860-8555 Japan
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3
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Kawano SI, Nakaya M, Saitow M, Ishiguro A, Yanai T, Onoe J, Tanaka K. Thermally Stable Array of Discrete C 60s on a Two-Dimensional Crystalline Adlayer of Macrocycles both in Vacuo and under Ambient Pressure. J Am Chem Soc 2022; 144:6749-6758. [PMID: 35315659 DOI: 10.1021/jacs.1c13610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A periodic monolayer array of discrete C60s was generated on an atomically flat Au(111) surface with the aid of a template adlayer. The template was a two-dimensional (2D) array of molecular pits prepared on an Au(111) surface through 2D crystallization of shape-persistent macrocycles composed of four carbazole and four salphens/Ni-salphens with a 1 nm hollow. Scanning tunneling microscopy imaging under ultra-high vacuum revealed that the square-shaped macrocycles, with 1.5 nm sides, were arranged with a periodic spacing of approximately 4.0 nm on the Au(111) surface, where the orientation and periodicity of the macrocycles were dependent on their chemical structures. After sublimation of C60s onto the adlayer, a single C60 molecule was entrapped in each pit, and an ordered molecular array of C60s was attained with a pattern similar to that of the macrocycles. The periodic pattern of C60s on the surface was thermally stable up to approximately 200 °C, even under ambient pressure. Scanning tunneling spectroscopy suggested the existence of an electronic interaction between the C60s and the Au(111) surface that was influenced by the macrocycle template on the surface.
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Affiliation(s)
- Shin-Ichiro Kawano
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Masato Nakaya
- Department of Energy Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan
| | - Masaaki Saitow
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Atsuki Ishiguro
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
| | - Takeshi Yanai
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan.,Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Chikusa, Nagoya 464-8601, Japan
| | - Jun Onoe
- Department of Energy Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa, Nagoya 464-8603, Japan
| | - Kentaro Tanaka
- Department of Chemistry, Graduate School of Science, Nagoya University, Chikusa, Nagoya 464-8602, Japan
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4
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Das S, Nascimbeni G, de la Morena RO, Ishiwari F, Shoji Y, Fukushima T, Buck M, Zojer E, Zharnikov M. Porous Honeycomb Self-Assembled Monolayers: Tripodal Adsorption and Hidden Chirality of Carboxylate Anchored Triptycenes on Ag. ACS NANO 2021; 15:11168-11179. [PMID: 34125529 PMCID: PMC8320238 DOI: 10.1021/acsnano.1c03626] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 06/08/2021] [Indexed: 06/12/2023]
Abstract
Molecules with tripodal anchoring to substrates represent a versatile platform for the fabrication of robust self-assembled monolayers (SAMs), complementing the conventional monopodal approach. In this context, we studied the adsorption of 1,8,13-tricarboxytriptycene (Trip-CA) on Ag(111), mimicked by a bilayer of silver atoms underpotentially deposited on Au. While tripodal SAMs frequently suffer from poor structural quality and inhomogeneous bonding configurations, the triptycene scaffold featuring three carboxylic acid anchoring groups yields highly crystalline SAM structures. A pronounced polymorphism is observed, with the formation of distinctly different structures depending on preparation conditions. Besides hexagonal molecular arrangements, the occurrence of a honeycomb structure is particularly intriguing as such an open structure is unusual for SAMs consisting of upright-standing molecules. Advanced spectroscopic tools reveal an equivalent bonding of all carboxylic acid anchoring groups. Notably, density functional theory calculations predict a chiral arrangement of the molecules in the honeycomb network, which, surprisingly, is not apparent in experimental scanning tunneling microscopy (STM) images. This seeming discrepancy between theory and experiment can be resolved by considering the details of the actual electronic structure of the adsorbate layer. The presented results represent an exemplary showcase for the intricacy of interpreting STM images of complex molecular films. They are also further evidence for the potential of triptycenes as basic building blocks for generating well-defined layers with unusual structural motifs.
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Affiliation(s)
- Saunak Das
- Angewandte
Physikalische Chemie, Universität
Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany
| | - Giulia Nascimbeni
- Institute
of Solid State Physics, NAWI Graz, Graz
University of Technology, Petersgasse 16, 8010 Graz, Austria
| | | | - Fumitaka Ishiwari
- Laboratory
for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
| | - Yoshiaki Shoji
- Laboratory
for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
| | - Takanori Fukushima
- Laboratory
for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta,
Midori-ku, Yokohama 226-8503, Japan
| | - Manfred Buck
- EaStCHEM
School of Chemistry, University of St Andrews, North Haugh, St Andrews KY16 9ST, U.K.
| | - Egbert Zojer
- Institute
of Solid State Physics, NAWI Graz, Graz
University of Technology, Petersgasse 16, 8010 Graz, Austria
| | - Michael Zharnikov
- Angewandte
Physikalische Chemie, Universität
Heidelberg, Im Neuenheimer Feld 253, D-69120 Heidelberg, Germany
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5
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Yin H, Xing K, Zhang Y, Dissanayake DMAS, Lu Z, Zhao H, Zeng Z, Yun JH, Qi DC, Yin Z. Periodic nanostructures: preparation, properties and applications. Chem Soc Rev 2021; 50:6423-6482. [PMID: 34100047 DOI: 10.1039/d0cs01146k] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Periodic nanostructures, a group of nanomaterials consisting of single or multiple nano units/components periodically arranged into ordered patterns (e.g., vertical and lateral superlattices), have attracted tremendous attention in recent years due to their extraordinary physical and chemical properties that offer a huge potential for a multitude of applications in energy conversion, electronic and optoelectronic applications. Recent advances in the preparation strategies of periodic nanostructures, including self-assembly, epitaxy, and exfoliation, have paved the way to rationally modulate their ferroelectricity, superconductivity, band gap and many other physical and chemical properties. For example, the recent discovery of superconductivity observed in "magic-angle" graphene superlattices has sparked intensive studies in new ways, creating superlattices in twisted 2D materials. Recent development in the various state-of-the-art preparations of periodic nanostructures has created many new ideas and findings, warranting a timely review. In this review, we discuss the current advances of periodic nanostructures, including their preparation strategies, property modulations and various applications.
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Affiliation(s)
- Hang Yin
- Research School of Chemistry, Australian National University, ACT 2601, Australia.
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6
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Wang RP, Yang B, Fu Q, Zhang Y, Zhu R, Dong XR, Zhang Y, Wang B, Yang JL, Luo Y, Dong ZC, Hou JG. Raman Detection of Bond Breaking and Making of a Chemisorbed Up-Standing Single Molecule at Single-Bond Level. J Phys Chem Lett 2021; 12:1961-1968. [PMID: 33591760 DOI: 10.1021/acs.jpclett.1c00074] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Probing bond breaking and making as well as related structural changes at the single-molecule level is of paramount importance for understanding the mechanism of chemical reactions. In this work, we report in situ tracking of bond breaking and making of an up-standing melamine molecule chemisorbed on Cu(100) by subnanometer resolved tip-enhanced Raman spectroscopy (TERS). We demonstrate a vertical detection depth of about 4 Å with spectral sensitivity at the single chemical-bond level, which allows us not only to justify the up-standing configuration involving a dehydrogenation process at the bottom upon chemisorption, but also to specify the breaking of top N-H bonds and the transformation to its tautomer during photon-induced hydrogen transfer reactions. Our results indicate the chemical and structural sensitivity of TERS for single-molecule recognition beyond flat-lying planar molecules, providing new opportunities for probing the microscopic mechanism of molecular adsorption and surface reactions at the chemical-bond level.
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Affiliation(s)
- Rui-Pu Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Ben Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Qiang Fu
- School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China
| | - Yao Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Rui Zhu
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Xiao-Ru Dong
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yang Zhang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Bing Wang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Jin-Long Yang
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Yi Luo
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - Zhen-Chao Dong
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
| | - J G Hou
- Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China
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7
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Carloni LE, Bezzu CG, Bonifazi D. Patterning Porous Networks through Self-Assembly of Programmed Biomacromolecules. Chemistry 2019; 25:16179-16200. [PMID: 31491049 DOI: 10.1002/chem.201902576] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 08/11/2019] [Indexed: 11/08/2022]
Abstract
Two-dimensional (2D) porous networks are of great interest for the fabrication of complex organized functional materials for potential applications in nanotechnologies and nanoelectronics. This review aims at providing an overview of bottom-up approaches towards the engineering of 2D porous networks by using biomacromolecules, with a particular focus on nucleic acids and proteins. The first part illustrates how the advancements in DNA nanotechnology allowed for the attainment of complex ordered porous two-dimensional DNA nanostructures, thanks to a biomimetic approach based on DNA molecules self-assembly through specific hydrogen-bond base pairing. The second part focuses the attention on how polypeptides and proteins structural properties could be used to engineer organized networks templating the formation of multifunctional materials. The structural organization of all examples is discussed as revealed by scanning probe microscopy or transmission electron microscopy imaging techniques.
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Affiliation(s)
- Laure-Elie Carloni
- Department of Chemistry and Namur Research College (NARC), University of Namur, Rue de Bruxelles 61, Namur, 5000, Belgium
| | - C Grazia Bezzu
- Cardiff University, School of Chemistry, Park Place, Main Building, CF10 3AT, Cardiff, Wales, UK
| | - Davide Bonifazi
- Cardiff University, School of Chemistry, Park Place, Main Building, CF10 3AT, Cardiff, Wales, UK
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8
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Zhu H, Niu T, Li A. Conformational Transitions of Phase-Separated Binary Molecules Assisted by Surface Dehalogenation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:3507-3512. [PMID: 30759989 DOI: 10.1021/acs.langmuir.8b04220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Molecular devices have become an emergent branch of nanoscience and technology beyond traditional silicon-based electronic devices. The properties of these devices are intimately related to the molecular conformation and packing. In this article, three different conformations of melamine molecules are observed on Au(111), and a transition from the lying-down to standing-up phase with long-range order is realized in melamine chains with the assistance of hexabromobenzene (HBB). We argue that it is the expanding of HBB domains from hexagonal to the dimer phase due to surface dehalogenation that facilitates the dehydrogenation of melamine to form a standing-up conformation. Similar transitions are also accomplished on the Ag(111) surface. Our results provide an effective way to achieve standing-up molecular arrays with long-range order on relatively less active metals. This may have significant implications in fabricating organic thin film transistors.
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Affiliation(s)
- Hailong Zhu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology , Chinese Academy of Sciences , Shanghai 200050 , People's Republic of China
- University of Chinese Academy of Sciences , Beijing 100049 , People's Republic of China
- CAS Center for Excellence in Superconducting Electronics (CENSE) , Shanghai 200050 , People's Republic of China
| | - Tianchao Niu
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology , Chinese Academy of Sciences , Shanghai 200050 , People's Republic of China
- CAS Center for Excellence in Superconducting Electronics (CENSE) , Shanghai 200050 , People's Republic of China
| | - Ang Li
- State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology , Chinese Academy of Sciences , Shanghai 200050 , People's Republic of China
- CAS Center for Excellence in Superconducting Electronics (CENSE) , Shanghai 200050 , People's Republic of China
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9
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Kerfoot J, Korolkov VV, Nizovtsev AS, Jones R, Taniguchi T, Watanabe K, Lesanovsky I, Olmos B, Besley NA, Besley E, Beton PH. Substrate-induced shifts and screening in the fluorescence spectra of supramolecular adsorbed organic monolayers. J Chem Phys 2018; 149:054701. [DOI: 10.1063/1.5041418] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- James Kerfoot
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Vladimir V. Korolkov
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Anton S. Nizovtsev
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Nikolaev Institute of Inorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, Academician Lavrentiev Avenue 3, 630090 Novosibirsk, Russian Federation
| | - Ryan Jones
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Takashi Taniguchi
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Kenji Watanabe
- National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan
| | - Igor Lesanovsky
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Beatriz Olmos
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
- Centre for the Mathematics and Theoretical Physics of Quantum Non-Equilibrium Systems, The University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Nicholas A. Besley
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Elena Besley
- School of Chemistry, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Peter H. Beton
- School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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10
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Cao N, Ding J, Yang B, Zhang J, Peng C, Lin H, Zhang H, Li Q, Chi L. Deprotonation-Induced Phase Evolutions in Co-Assembled Molecular Structures. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:7852-7858. [PMID: 29886745 DOI: 10.1021/acs.langmuir.8b00228] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
In this work, we systematically studied the co-assembly behavior of 1,3,5-tris(4-carboxyphenyl)benzene (TCPB) and 4,4″-diamino- p-terphenyl (DATP) on a silver surface. Due to the thermal instability of carboxylic acids, the co-assembled structure exhibits temperature-dependent evolutions on Ag(111). The level of the deprotonation reactions of TCPB are clarified by the characteristic self-assembled footprints. Aided by these footprints, we are able to identify the structures of the complex co-assembly of TCPB and DATP entities at each stage. Finally, the conclusions are further evidenced by density functional theory calculations.
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Affiliation(s)
- Nan Cao
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Jinqiang Ding
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Biao Yang
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Junjie Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Chencheng Peng
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Haiping Lin
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Haiming Zhang
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Qing Li
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
| | - Lifeng Chi
- Institute of Functional Nano & Soft Materials (FUNSOM) and Jiangsu Key Laboratory for Carbon-Based Functional Materials & Devices , Soochow University , Suzhou 215123 , P. R. China
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11
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Yan L, Kuang G, Lin N. Phase separation and selective guest–host binding in multi-component supramolecular self-assembly on Au(111). Chem Commun (Camb) 2018; 54:10570-10573. [DOI: 10.1039/c8cc04491k] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We find a phase separation and selective guest–host inclusion in the self-assembly of trimesic acid, benzenetribenzoic acid and coronene on Au(111).
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Affiliation(s)
- Linghao Yan
- Department of Physics
- The Hong Kong University of Science and Technology
- China
| | - Guowen Kuang
- Department of Physics
- The Hong Kong University of Science and Technology
- China
| | - Nian Lin
- Department of Physics
- The Hong Kong University of Science and Technology
- China
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12
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Judd CJ, Champness NR, Saywell A. An On-Surface Reaction Confined within a Porous Molecular Template. Chemistry 2017; 24:56-61. [PMID: 29065224 DOI: 10.1002/chem.201704693] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Indexed: 11/07/2022]
Abstract
On-surface reactions based on metal-catalysed Ullmann coupling have been successfully employed to synthesise a wide variety of covalently coupled structures. Substrate chemistry and topology are both known to effect the progression of an on-surface reaction; offering routes to control efficiency and selectivity. Here, we detail ultra-high vacuum scanning probe microscopy experiments showing that templating a catalytically active surface, via a supramolecular template, influences the reaction pathway of an on-surface Ullmann-type coupling reaction by inhibiting one potential intermediate structure and stabilising another.
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Affiliation(s)
- Chris J Judd
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Neil R Champness
- School of Chemistry, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
| | - Alex Saywell
- School of Physics and Astronomy, The University of Nottingham, Nottingham, NG7 2RD, United Kingdom
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13
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Supramolecular networks stabilise and functionalise black phosphorus. Nat Commun 2017; 8:1385. [PMID: 29123112 PMCID: PMC5680224 DOI: 10.1038/s41467-017-01797-6] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Accepted: 10/16/2017] [Indexed: 11/09/2022] Open
Abstract
The limited stability of the surface of black phosphorus (BP) under atmospheric conditions is a significant constraint on the exploitation of this layered material and its few layer analogue, phosphorene, as an optoelectronic material. Here we show that supramolecular networks stabilised by hydrogen bonding can be formed on BP, and that these monolayer-thick films can passivate the BP surface and inhibit oxidation under ambient conditions. The supramolecular layers are formed by solution deposition and we use atomic force microscopy to obtain images of the BP surface and hexagonal supramolecular networks of trimesic acid and melamine cyanurate (CA.M) under ambient conditions. The CA.M network is aligned with rows of phosphorus atoms and forms large domains which passivate the BP surface for more than a month, and also provides a stable supramolecular platform for the sequential deposition of 1,2,4,5-tetrakis(4-carboxyphenyl)benzene to form supramolecular heterostructures.
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14
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Bouju X, Mattioli C, Franc G, Pujol A, Gourdon A. Bicomponent Supramolecular Architectures at the Vacuum–Solid Interface. Chem Rev 2017; 117:1407-1444. [DOI: 10.1021/acs.chemrev.6b00389] [Citation(s) in RCA: 78] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Xavier Bouju
- CEMES-CNRS, 29 Rue J. Marvig, 31055 Toulouse, France
| | | | - Grégory Franc
- CEMES-CNRS, 29 Rue J. Marvig, 31055 Toulouse, France
| | - Adeline Pujol
- Université de Toulouse, UPS, CNRS, CEMES, 118 route de Narbonne, 31062 Toulouse, France
| | - André Gourdon
- CEMES-CNRS, 29 Rue J. Marvig, 31055 Toulouse, France
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15
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Rochford LA, Jones TS, Nielsen CB. Epitaxial Templating of C60 with a Molecular Monolayer. J Phys Chem Lett 2016; 7:3487-3490. [PMID: 27540868 DOI: 10.1021/acs.jpclett.6b01656] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Commensurate epitaxial monolayers of truxenone on Cu (111) were employed to template the growth of monolayer and bilayer C60. Through the combination of STM imaging and LEED analysis we have demonstrated that C60 forms a commensurate 8 × 8 overlayer on truxenone/Cu (111). Bilayers of C60 retain the 8 × 8 periodicity of templated monolayers and although Kagome lattice arrangements are observed these are explained with combinations of 8 × 8 symmetry.
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Affiliation(s)
- L A Rochford
- Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - T S Jones
- Department of Chemistry, University of Warwick , Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
| | - C B Nielsen
- Materials Research Institute and School of Biological and Chemical Sciences, Queen Mary University of London , Mile End Road, London E1 4NS, United Kingdom
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16
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Müller K, Enache M, Stöhr M. Confinement properties of 2D porous molecular networks on metal surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2016; 28:153003. [PMID: 26982214 DOI: 10.1088/0953-8984/28/15/153003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Quantum effects that arise from confinement of electronic states have been extensively studied for the surface states of noble metals. Utilizing small artificial structures for confinement allows tailoring of the surface properties and offers unique opportunities for applications. So far, examples of surface state confinement include thin films, artificial nanoscale structures, vacancy and adatom islands, self-assembled 1D chains, vicinal surfaces, quantum dots and quantum corrals. In this review we summarize recent achievements in changing the electronic structure of surfaces by adsorption of nanoporous networks whose design principles are based on the concepts of supramolecular chemistry. Already in 1993, it was shown that quantum corrals made from Fe atoms on a Cu(1 1 1) surface using single atom manipulation with a scanning tunnelling microscope confine the Shockley surface state. However, since the atom manipulation technique for the construction of corral structures is a relatively time consuming process, the fabrication of periodic two-dimensional (2D) corral structures is practically impossible. On the other side, by using molecular self-assembly extended 2D porous structures can be achieved in a parallel process, i.e. all pores are formed at the same time. The molecular building blocks are usually held together by non-covalent interactions like hydrogen bonding, metal coordination or dipolar coupling. Due to the reversibility of the bond formation defect-free and long-range ordered networks can be achieved. However, recently also examples of porous networks formed by covalent coupling on the surface have been reported. By the choice of the molecular building blocks, the dimensions of the network (pore size and pore to pore distance) can be controlled. In this way, the confinement properties of the individual pores can be tuned. In addition, the effect of the confined state on the hosting properties of the pores will be discussed in this review article.
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Affiliation(s)
- Kathrin Müller
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen, The Netherlands. Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569 Stuttgart, Germany
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17
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Jarvis SP. Resolving Intra- and Inter-Molecular Structure with Non-Contact Atomic Force Microscopy. Int J Mol Sci 2015; 16:19936-59. [PMID: 26307976 PMCID: PMC4581333 DOI: 10.3390/ijms160819936] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2015] [Revised: 07/24/2015] [Accepted: 07/30/2015] [Indexed: 11/25/2022] Open
Abstract
A major challenge in molecular investigations at surfaces has been to image individual molecules, and the assemblies they form, with single-bond resolution. Scanning probe microscopy, with its exceptionally high resolution, is ideally suited to this goal. With the introduction of methods exploiting molecularly-terminated tips, where the apex of the probe is, for example, terminated with a single CO, Xe or H2 molecule, scanning probe methods can now achieve higher resolution than ever before. In this review, some of the landmark results related to attaining intramolecular resolution with non-contact atomic force microscopy (NC-AFM) are summarised before focussing on recent reports probing molecular assemblies where apparent intermolecular features have been observed. Several groups have now highlighted the critical role that flexure in the tip-sample junction plays in producing the exceptionally sharp images of both intra- and apparent inter-molecular structure. In the latter case, the features have been identified as imaging artefacts, rather than real intermolecular bonds. This review discusses the potential for NC-AFM to provide exceptional resolution of supramolecular assemblies stabilised via a variety of intermolecular forces and highlights the potential challenges and pitfalls involved in interpreting bonding interactions.
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Affiliation(s)
- Samuel Paul Jarvis
- School of Physics & Astronomy, University of Nottingham, Nottingham NG7 2RD, UK.
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18
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Würthner F, Saha-Möller CR, Fimmel B, Ogi S, Leowanawat P, Schmidt D. Perylene Bisimide Dye Assemblies as Archetype Functional Supramolecular Materials. Chem Rev 2015; 116:962-1052. [PMID: 26270260 DOI: 10.1021/acs.chemrev.5b00188] [Citation(s) in RCA: 969] [Impact Index Per Article: 107.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Frank Würthner
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Chantu R Saha-Möller
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Benjamin Fimmel
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Soichiro Ogi
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - Pawaret Leowanawat
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
| | - David Schmidt
- Institut für Organische Chemie and Center for Nanosystems Chemistry, Universität Würzburg , Am Hubland, 97074 Würzburg, Germany
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19
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Korolkov VV, Svatek SA, Allen S, Roberts CJ, Tendler SJB, Taniguchi T, Watanabe K, Champness NR, Beton PH. Bimolecular porous supramolecular networks deposited from solution on layered materials: graphite, boron nitride and molybdenum disulphide. Chem Commun (Camb) 2015; 50:8882-5. [PMID: 24969532 DOI: 10.1039/c4cc03720k] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A two-dimensional porous network formed from perylene tetracarboxylic diimide (PTCDI) and melamine may be deposited from solution on the surfaces of highly oriented pyrolytic graphite (HOPG), hexagonal boron nitride (hBN) and molybdenum disulphide (MoS2). Images acquired using high resolution atomic force microscopy (AFM) operating under ambient conditions have revealed that the network forms extended ordered monolayers (>1 μm(2)) on HOPG and hBN whereas on MoS2 much smaller islands are observed.
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Affiliation(s)
- Vladimir V Korolkov
- School of Physics & Astronomy, The University of Nottingham, Nottingham NG7 2RD, UK.
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20
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Tahara K, Gotoda J, Carroll CN, Hirose K, De Feyter S, Tobe Y. Square Tiling by Square Macrocycles at the Liquid/Solid Interface: Co-crystallisation with One- or Two-Dimensional Order. Chemistry 2015; 21:6806-16. [DOI: 10.1002/chem.201500026] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Indexed: 11/09/2022]
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21
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Zhang JL, Zhong S, Zhong JQ, Niu TC, Hu WP, Wee ATS, Chen W. Rational design of two-dimensional molecular donor-acceptor nanostructure arrays. NANOSCALE 2015; 7:4306-24. [PMID: 25684203 DOI: 10.1039/c4nr06741j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The construction of long-range ordered organic donor-acceptor nanostructure arrays over microscopic areas supported on solid substrates is one of the most challenging tasks towards the realization of molecular nanodevices. They can also be used as ideal model systems to understand light induced charge transfer, charge separation and energy conversion processes and mechanisms at the nanometer scale. The aim of this paper is to highlight recent advances and progress in this topic. Special attention is given to two different strategies for the construction of organic donor-acceptor nanostructure arrays, namely (i) molecular self-assembly on artificially patterned or pre-defined molecular surface nanotemplates and (ii) molecular nanostructure formation steered via directional and selective intermolecular interactions. The interfacial charge transfer and the energy level alignment of these donor-acceptor nanostructures are also discussed.
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Affiliation(s)
- Jia Lin Zhang
- Department of Physics, National University of Singapore, 2 Science Drive 3, 117542, Singapore
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22
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Miller DP, Simpson S, Tymińska N, Zurek E. Benzene derivatives adsorbed to the Ag(111) surface: Binding sites and electronic structure. J Chem Phys 2015; 142:101924. [DOI: 10.1063/1.4908267] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Affiliation(s)
- Daniel P. Miller
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
| | - Scott Simpson
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
- School of Science, Penn State Erie, The Behrend College, 4205 College Drive, Erie, Pennsylvania 16563, USA
| | - Nina Tymińska
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
| | - Eva Zurek
- Department of Chemistry, State University of New York at Buffalo, Buffalo, New York 14260-3000, USA
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23
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Hieulle J, Peyrot D, Jiang Z, Silly F. Engineering two-dimensional hybrid NaCl–organic coordinated nanoarchitectures on metal surfaces. Chem Commun (Camb) 2015; 51:13162-5. [DOI: 10.1039/c5cc01892g] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We selectively engineer three two-dimensional self-assembled hybrid PTCDI–NaCl nanoarchitectures,i.e.a flower-structure, a mesh-structure and a chain-structure on Au(111).
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24
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Slater AG, Perdigão LMA, Beton PH, Champness NR. Surface-based supramolecular chemistry using hydrogen bonds. Acc Chem Res 2014; 47:3417-27. [PMID: 25330179 DOI: 10.1021/ar5001378] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CONSPECTUS: The arrangement of molecular species into extended structures remains the focus of much current chemical science. The organization of molecules on surfaces using intermolecular interactions has been studied to a lesser degree than solution or solid-state systems, and unanticipated observations still lie in store. Intermolecular hydrogen bonds are an attractive tool that can be used to facilitate the self-assembly of an extended structure through the careful design of target building blocks. Our studies have focused on the use of 3,4,9,10-perylene tetracarboxylic acid diimides (PTCDIs), and related functionalized analogues, to prepare extended arrays on surfaces. These molecules are ideal for such studies because they are specifically designed to interact with appropriate diaminopyridine-functionalized molecules, and related species, through complementary hydrogen bonds. Additionally, PTCDI species can be functionalized in the bay region of the molecule, facilitating modification of the self-assembled structures that can be prepared. Through a combination of PTCDI derivatives, sometimes in combination with melamine, porous two-dimensional arrays can be formed that can entrap guest molecules. The factors that govern the self-assembly processes of PTCDI derivatives are discussed, and the ability to construct suitable target arrays and host-specific molecular species, including fullerenes and transition metal clusters, is demonstrated.
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Affiliation(s)
- Anna G. Slater
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Luis M. A. Perdigão
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Peter H. Beton
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Neil R. Champness
- School of Chemistry, ‡School of Physics
and Astronomy, University of Nottingham, Nottingham NG7 2RD, United Kingdom
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25
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Karmel HJ, Chien T, Demers-Carpentier V, Garramone JJ, Hersam MC. Self-Assembled Two-Dimensional Heteromolecular Nanoporous Molecular Arrays on Epitaxial Graphene. J Phys Chem Lett 2014; 5:270-274. [PMID: 26270698 DOI: 10.1021/jz4025518] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The development of graphene functionalization strategies that simultaneously achieve two-dimensional (2D) spatial periodicity and substrate registry is of critical importance for graphene-based nanoelectronics and related technologies. Here, we demonstrate the generation of a hydrogen-bonded molecularly thin organic heteromolecular nanoporous network on epitaxial graphene on SiC(0001) using room-temperature ultrahigh vacuum scanning tunneling microscopy. In particular, perylenetetracarboxylic diimide (PTCDI) and melamine are intermixed to form a spatially periodic 2D nanoporous network architecture with hexagonal symmetry and a lattice parameter of 3.45 ± 0.10 nm. The resulting adlayer is in registry with the underlying graphene substrate and possesses a characteristic domain size of 40-50 nm. This molecularly defined nanoporous network holds promise as a template for 2D ordered chemical modification of graphene at lengths scales relevant for graphene band structure engineering.
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26
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Li Z, Chen G, Xu Y, Wang X, Wang Z. Study of the structural and the spectral characteristics of [C3N3(NH2)3]n (n = 1-4) clusters. J Phys Chem A 2013; 117:12511-8. [PMID: 24224616 DOI: 10.1021/jp405087u] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Previous research has shown that interactions between melamine molecules within a cluster can give rise to the molecular self-assembly and that the spectral characteristic of melamine can be used to inspect melamine in a carrier. Although the structural and spectral characteristics of an isolated single melamine molecule and the molecular arrays on metal or semiconductor surfaces have been studied extensively, little is known about that of isolated multimolecular melamine clusters. In this work, density functional theory (DFT) calculations at the ω-B97XD/6-311++G(d,p) level were performed to study the structural and spectral characteristics of isolated melamine clusters [C3N3(NH2)3]n (n = 1-4) in the ground state. The calculation shows that a ground-state single melamine molecule takes a quasi-planar structure. The C and N atoms of the molecule are in one plane, which we call the molecular plane, while the H atoms deviate slightly from the molecular plane. When melamine molecules gather to form a cluster, the intermolecular hydrogen bonds (IHBs) N-H···N will arise, with the lengths of H···N in the range from 1.960 to 1.970 Å; the length of N-H will be elongated to 1.022 Å from its original of 1.004 Å, the N-H···N bond angles will be about 176°, and the average single-bond binding energy will be approximately -0.285 eV. In a multimolecular cluster, each melamine molecule still takes the quasi-planar structure. Each molecular plane in the cluster retains a planar structure, and some H atoms diverge more from their molecular planes. The molecular planes in a cluster are not coplanar, and the dihedral angle between the molecular planes of two neighboring melamine molecules ranges from 38 to 40°. In addition, the theoretical study of the infrared (IR) spectrum and nuclear magnetic resonance (NMR) spectrum of [C3N3(NH2)3]n (n = 1-4) was conducted. The results confirm the existence of IHBs in a multimolecular melamine cluster and reveal the symmetry of the electron cloud distribution in the melamine clusters. Experimental study of the IR for solid-state melamine and (13)C NMR spectra for both solid- and liquid-state melamine samples were also carried out, in which the corresponding spectral characteristics of [C3N3(NH2)3]n (n = 2-4) clusters deduced from theoretical study were observed. Findings of this study may serve as theoretical references for future identification and utilization of melamine clusters.
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Affiliation(s)
- Zhenzhang Li
- College of Science, South China Agriculture University , Guangzhou 510642, People's Republic of China
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27
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Slater AG, Davies ES, Argent SP, Lewis W, Blake AJ, McMaster J, Champness NR. Bis-thioether-substituted perylene diimides: structural, electrochemical, and spectroelectrochemical properties. J Org Chem 2013; 78:2853-62. [PMID: 23506219 DOI: 10.1021/jo400026r] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The synthesis and separation of the 1,6- and 1,7- isomers of N,N'-bis(alkyl)diadamantylthio-3,4,9,10-perylenetetracarboxylic acid diimide are reported. Investigations of the structural, electrochemical, spectroscopic, and spectroelectrochemical properties of the isomers reveal a sequence of electrochemically and chemically reversible reduction processes for both isomers. Three X-ray crystal structures are reported including a pair of 1,6- and 1,7-isomers demonstrating the twist of the perylene core in the solid state. Our studies thoroughly characterize the mono- and direduced states of the two isomers allowing unequivocal characterization of the reduced species by UV-vis and IR spectroscopic measurements. EPR studies also allow direct identification of the monoreduced PTCDI species and spectroscopic measurements confirm the delocalization of electronic density around the carbonyl moieties of the reduced species.
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Affiliation(s)
- Anna G Slater
- School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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28
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Greenwood J, Baddeley CJ. Formation of imine oligomers on Au under ambient conditions investigated by scanning tunneling microscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:653-657. [PMID: 23252973 DOI: 10.1021/la304506s] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Scanning tunneling microscopy has been used to investigate the nucleophilic substitution reaction between melamine (1,3,5-triazine-2,4,6-triamine) and terephthalaldehyde on Au/mica following deposition from solution in ambient conditions. The reaction is observed to proceed at room temperature over a time scale of days with the formation of imine oligomers intermixed with melamine islands on the Au surface. The oligomers ultimately self-assemble into a porous arrangement. The mechanism and extent of the surface confined reactions are discussed.
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Affiliation(s)
- J Greenwood
- EaStCHEM School of Chemistry, University of St. Andrews, St. Andrews, Fife, UK
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29
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Zhang JL, Niu TC, Wee ATS, Chen W. Self-assembly of binary molecular nanostructure arrays on graphite. Phys Chem Chem Phys 2013; 15:12414-27. [DOI: 10.1039/c3cp00023k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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30
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Cebula I, Räisänen MT, Madueno R, Karamzadeh B, Buck M. Comment on “The structure and formation of hydrogen-bonded molecular networks on Au(111) surfaces revealed by scanning tunnelling and torsional-tapping atomic force microscopy” by V. V. Korolkov, N. Mullin, S. Allen, C. J. Roberts, J. K. Hobbs and S. J. B. Tendler, Phys. Chem. Chem. Phys., 2012, 14, 15909. Phys Chem Chem Phys 2013; 15:14126-7. [DOI: 10.1039/c3cp50754h] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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31
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Korolkov VV, Mullin N, Allen S, Roberts CJ, Hobbs JK, Tendler SJB. Reply to the ‘Comment on “The structure and formation of hydrogen-bonded molecular networks on Au(111) surfaces revealed by scanning tunnelling and torsional-tapping atomic force microscopy”’ by I. Cebula, M. T. Räisänen, R. Madueno, B. Karamzadeh and M. Buck, Phys. Chem. Chem. Phys., 2013, 15, DOI: 10.1039/c3cp50754h. Phys Chem Chem Phys 2013; 15:14128-9. [DOI: 10.1039/c3cp52256c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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32
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Korolkov VV, Mullin N, Allen S, Roberts CJ, Hobbs JK, Tendler SJB. The structure and formation of hydrogen-bonded molecular networks on Au(111) surfaces revealed by scanning tunnelling and torsional-tapping atomic force microscopy. Phys Chem Chem Phys 2012; 14:15909-16. [PMID: 23093335 DOI: 10.1039/c2cp43199h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A comprehensive scanning probe microscopy study has been carried out to characterise 3,4,9,10-Perylenetetracarboxylic diimide (PTCDI)-melamine hydrogen-bonded networks deposited on Au(111)-surfaces. Both scanning tunnelling and atomic force microscopy were utilized. Such complementary analysis revealed a multilayered structure of the networks on the Au(111)-surface as opposed to a widely reported monolayer structure. Details of the network formation mechanism are presented. We have also demonstrated that despite the apparent network stability in ambient conditions it is unstable in aqueous solutions of pH 4.5 and 7.1.
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Affiliation(s)
- Vladimir V Korolkov
- Laboratory of Biophysics and Surface Analysis, School of Pharmacy, The University of Nottingham, Nottingham, NG7 2RD, UK
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33
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Mura M, Silly F, Burlakov V, Castell MR, Briggs GAD, Kantorovich LN. Formation mechanism for a hybrid supramolecular network involving cooperative interactions. PHYSICAL REVIEW LETTERS 2012; 108:176103. [PMID: 22680886 DOI: 10.1103/physrevlett.108.176103] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2012] [Indexed: 06/01/2023]
Abstract
A novel mechanism of hybrid assembly of molecules on surfaces is proposed stemming from interactions between molecules and on-surface metal atoms which eventually got trapped inside the network pores. Based on state-of-the-art theoretical calculations, we find that the new mechanism relies on formation of molecule-metal atom pairs which, together with molecules themselves, participate in the assembly growth. Most remarkably, the dissociation of pairs is facilitated by a cooperative interaction involving many molecules. This new mechanism is illustrated on a low coverage Melamine hexagonal network on the Au(111) surface where multiple events of gold atoms trapping via a set of so-called "gate" transitions are found by kinetic Monte Carlo simulations based on transition rates obtained using ab initio density functional theory calculations and the nudged elastic band method. Simulated STM images of gold atoms trapped in the pores of the Melamine network predict that the atoms should appear as bright spots inside Melamine hexagons. No trapping was found at large Melamine coverages, however. These predictions have been supported by preliminary STM experiments which show bright spots inside Melamine hexagons at low Melamine coverages, while empty pores are mostly observed at large coverages. Therefore, we suggest that bright spots sometimes observed in the pores of molecular assemblies on metal surfaces may be attributed to trapped substrate metal atoms. We believe that this type of mechanism could be used for delivering adatom species of desired functionality (e.g., magnetic) into the pores of hydrogen-bonded networks serving as templates for their capture.
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Affiliation(s)
- Manuela Mura
- Physics, King's College London, The Strand, London, United Kingdom
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34
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35
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Phillips AG, Beton PH, Champness NR. Two-Dimensional Supramolecular Chemistry. Supramol Chem 2012. [DOI: 10.1002/9780470661345.smc202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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36
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Yoshimoto S, Itaya K. Advances in supramolecularly assembled nanostructures of fullerenes and porphyrins at surfaces. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424607000369] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The ‘bottom-up’ strategy is an attractive and promising approach for the construction of nanoarchitectures. Supramolecular assemblies based on non-covalent interactions have been explored in an attempt to control surface properties. In this minireview, we focus on advances made in the past three years in the field of scanning tunneling microscopy (STM) on supramolecular assembly and the function of porphyrins, phthalocyanines, and fullerenes, non-covalently bound on metal single crystal surfaces. Well-defined adlayers, consisting of porphyrin and phthalocyanine for the design of supramolecular nanoarchitectures, supramolecular traps of C 60 on hydrogen bond networks, a unique approach for controlling molecular orientation by a 1:1 supramolecularly assembled film consisting of C 60 and the related derivatives and metallooctaethylporphyrins, and nanoapplications of fullerenes, either induced by tip manipulation or driven by thermal fluctuations at surfaces, were clearly visualized by STM.
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Affiliation(s)
- Soichiro Yoshimoto
- National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Kingo Itaya
- Department of Applied Chemistry, Graduate School of Engineering, Tohoku University, 6-6-07 Aoba, Sendai 980-8579, Japan
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37
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Räisänen MT, Slater (née Phillips) AG, Champness NR, Buck M. Effects of pore modification on the templating of guest molecules in a 2D honeycomb network. Chem Sci 2012. [DOI: 10.1039/c1sc00543j] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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38
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Shen YT, Deng K, Zhang XM, Feng W, Zeng QD, Wang C, Gong JR. Switchable ternary nanoporous supramolecular network on photo-regulation. NANO LETTERS 2011; 11:3245-50. [PMID: 21732625 DOI: 10.1021/nl201504x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Controlled regulation of the switchable behavior of the supramolecular network is central to the potential application in the molecular scale nanodevices. In this work, it is reported that the reversible accommodation of the guest molecules in the nanoporous supramolecular network can be regulated by the UV/visible light. The nanoporous complex template of TCDB/4NN-Macrocycle(trans,trans,trans,trans) with photosensitive units is well-defined. After the UV irradiation, the template can be switched on to encapsulate coronene molecules due to the formation of a new photoisomer(trans,cis,trans,cis) and switched off to expel coronene from the inner cavities under the visible light. The photoregulated switchable multicomponent supramolecular guest-host network provides a novel strategy for fabricating the functional nanodevices at the molecular scale.
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Affiliation(s)
- Yong-Tao Shen
- National Center for Nanoscience and Technology, 11 Zhongguancun Beiyitiao, Beijing 100190, People's Republic of China
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Liang H, Sun W, Jin X, Li H, Li J, Hu X, Teo BK, Wu K. Two-Dimensional Molecular Porous Networks Formed by Trimesic Acid and 4,4′-Bis(4-pyridyl)biphenyl on Au(111) through Hierarchical Hydrogen Bonds: Structural Systematics and Control of Nanopore Size and Shape. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201101477] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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40
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Liang H, Sun W, Jin X, Li H, Li J, Hu X, Teo BK, Wu K. Two-Dimensional Molecular Porous Networks Formed by Trimesic Acid and 4,4′-Bis(4-pyridyl)biphenyl on Au(111) through Hierarchical Hydrogen Bonds: Structural Systematics and Control of Nanopore Size and Shape. Angew Chem Int Ed Engl 2011; 50:7562-6. [DOI: 10.1002/anie.201101477] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2011] [Indexed: 11/09/2022]
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41
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Ciesielski A, Samorì P. Supramolecular assembly/reassembly processes: molecular motors and dynamers operating at surfaces. NANOSCALE 2011; 3:1397-1410. [PMID: 21350766 DOI: 10.1039/c0nr00914h] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Among the many significant advances within the field of supramolecular chemistry over the past decades, the development of the so-called "dynamers" features a direct relevance to materials science. Defined as "combinatorial dynamic polymers", dynamers are constitutional dynamic systems and materials resulting from the application of the principles of supramolecular chemistry to polymer science. Like supramolecular materials in general, dynamers are reversible dynamic multifunctional architectures, capable of modifying their constitution by exchanging, recombining, incorporating components. They may exhibit a variety of novel properties and behave as adaptive materials. In this review we focus on the design of responsive switchable monolayers, i.e. monolayers capable to undergo significant changes in their physical or chemical properties as a result of external stimuli. Scanning tunneling microscopy studies provide direct evidence with a sub-nanometre resolution, on the formation and dynamic response of these self-assembled systems featuring controlled geometries and properties.
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Affiliation(s)
- Artur Ciesielski
- Nanochemistry Laboratory, ISIS-CNRS 7006, Université de Strasbourg, 8 allée Gaspard Monge, 67000, Strasbourg, France
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42
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Uemura S, Aono M, Komatsu T, Kunitake M. Two-dimensional self-assembled structures of melamine and melem at the aqueous solution-Au(111) interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:1336-1340. [PMID: 21126043 DOI: 10.1021/la103948n] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Self-assembled structures of melamine and the condensed melamine derivative melem were investigated at aqueous solution-Au(111) interfaces by cyclic voltammetry and in situ scanning tunneling microscopy (STM) observation. The adsorption/desorption behaviors of both molecules on Au(111) surfaces could be controlled by varying the electrochemical potential and solution concentration. In the negative potential region, self-assembled structures of melem and melamine were constructed by double hydrogen bonding systems between nitrogen atoms of triazine rings and amine groups. In addition, melem formed a closely packed structure at potentials of between -0.3 and -0.15 V or in solutions at higher concentrations.
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Affiliation(s)
- Shinobu Uemura
- Graduate School of Science and Technology, Kumamoto University, Kumamoto, Japan
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43
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Cañas-Ventura ME, Aït-Mansour K, Ruffieux P, Rieger R, Müllen K, Brune H, Fasel R. Complex interplay and hierarchy of interactions in two-dimensional supramolecular assemblies. ACS NANO 2011; 5:457-469. [PMID: 21186825 DOI: 10.1021/nn102164g] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
In order to address the interplay of hydrogen bonding, dipolar interactions, and metal coordination, we have investigated the two-dimensional mono- and bicomponent self-assembly of three closely related diaminotriazine-based molecular building blocks and a complementary perylenetetracarboxylic diimide by means of scanning tunneling microscopy. The simplest molecular species, bis-diaminotriazine-benzene, only interacts via hydrogen bonds and forms a unique supramolecular pattern on the Au(111) surface. For the two related molecular species, which exhibit in addition to hydrogen bonding also dipolar interactions and metal coordination, the number of distinct supramolecular structures increases dramatically with the number of possible interaction channels. Deposition together with the complementary perylene species, however, always results in a single well-defined supramolecular arrangement of molecules. A detailed analysis of the observed mono- and bicomponent assemblies allows shedding light on the hierarchy of the competing interactions, with important implications for the fabrication of surface-supported supramolecular networks by design.
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Affiliation(s)
- Marta E Cañas-Ventura
- Institute of Condensed Matter Physics (ICMP), Ecole Polytechnique Fédérale de Lausanne (EPFL), Station 3, 1015 Lausanne, Switzerland
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44
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Slater (née Phillips) AG, Beton PH, Champness NR. Two-dimensional supramolecular chemistry on surfaces. Chem Sci 2011. [DOI: 10.1039/c1sc00251a] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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45
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Eichhorn J, Schlögl S, Lotsch BV, Schnick W, Heckl WM, Lackinger M. Self-assembly of melem on Ag(111)—emergence of porous structures based on amino-heptazine hydrogen bonds. CrystEngComm 2011. [DOI: 10.1039/c1ce05342f] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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46
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Self-assembled aggregates formed by single-molecule magnets on a gold surface. Nat Commun 2010; 1:75. [DOI: 10.1038/ncomms1075] [Citation(s) in RCA: 97] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2010] [Accepted: 08/23/2010] [Indexed: 02/05/2023] Open
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47
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Yu M, Kalashnyk N, Xu W, Barattin R, Benjalal Y, Laegsgaard E, Stensgaard I, Hliwa M, Bouju X, Gourdon A, Joachim C, Besenbacher F, Linderoth TR. Supramolecular architectures on surfaces formed through hydrogen bonding optimized in three dimensions. ACS NANO 2010; 4:4097-4109. [PMID: 20550141 DOI: 10.1021/nn100450q] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Supramolecular self-assembly on surfaces, guided by hydrogen bonding interactions, has been widely studied, most often involving planar compounds confined directly onto surfaces in a planar two-dimensional (2-D) geometry and equipped with structurally rigid chemical functionalities to direct the self-assembly. In contrast, so-called molecular Landers are a class of compounds that exhibit a pronounced three-dimensional (3-D) structure once adsorbed on surfaces, arising from a molecular backboard equipped with bulky groups which act as spacer legs. Here we demonstrate the first examples of extended, hydrogen-bonded surface architectures formed from molecular Landers. Using high-resolution scanning tunnelling microscopy (STM) under well controlled ultrahigh vacuum conditions we characterize both one-dimensional (1-D) chains as well as five distinct long-range ordered 2-D supramolecular networks formed on a Au(111) surface from a specially designed Lander molecule equipped with dual diamino-triazine (DAT) functional moieties, enabling complementary NH...N hydrogen bonding. Most interestingly, comparison of experimental results to STM image calculations and molecular mechanics structural modeling demonstrates that the observed molecular Lander-DAT structures can be rationalized through characteristic intermolecular hydrogen bonding coupling motifs which would not have been possible in purely planar 2-D surface assembly because they involve pronounced 3-D optimization of the bonding configurations. The described 1-D and 2-D patterns of Lander-DAT molecules may potentially be used as extended molecular molds for the nucleation and growth of complex metallic nanostructures.
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Affiliation(s)
- Miao Yu
- Interdisciplinary Nanoscience Center (iNANO) and Department of Physics and Astronomy Aarhus University, 8000 Aarhus, Denmark
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48
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Villagomez CJ, Guillermet O, Goudeau S, Ample F, Xu H, Coudret C, Bouju X, Zambelli T, Gauthier S. Self-assembly of enantiopure domains: the case of indigo on Cu(111). J Chem Phys 2010; 132:074705. [PMID: 20170242 DOI: 10.1063/1.3314725] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The adsorption of indigo molecules on Cu(111) was investigated by low temperature (5 K) scanning tunneling microscopy from the isolated single molecule regime to one monolayer. Structural optimization and image calculations demonstrate that the molecules are in a physisorbed state. Because of the reduced symmetry at the surface, single molecules acquire a chiral character upon adsorption leading to a two-dimensional (2D) chirality. They adopt two adsorption configurations, related by a mirror symmetry of the substrate, each with a distinct molecular orientation. Consequently, the 2D chirality is expressed by the orientation of the molecule. For higher coverage, molecules self-assemble by hydrogen bonding in nearly homochiral molecular chains, whose orientation is determined by the orientation taken by the isolated molecules. When the coverage approaches one monolayer, these chains pack into domains. Finally, the completion of the monolayer induces the expulsion of the molecules of the wrong chirality that are still in these domains, leading to perfect resolution in enantiopure domains.
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Affiliation(s)
- C J Villagomez
- The NanoSciences Group, Centre d'élaboration de matériaux et d'études structurales (CEMES) CNRS and University of Toulouse III Paul Sabatier, 29 rue Jeanne-Marvig, BP 94347, F-31005 Toulouse Cedex 4, France
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Tsai TH, Thiagarajan S, Chen SM. Detection of melamine in milk powder and human urine. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2010; 58:4537-4544. [PMID: 20353183 DOI: 10.1021/jf904554s] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Detection of melamine has been developed by employing oxidized polycrystalline gold electrode (poly GE). The poly GE was directly utilized for the detection of melamine using differential pulse voltammetry (DPV) and impedimetry. Poly GE successfully showed the oxidation peak for melamine adsorption at 1.1 V is purely based on the detection of adsorption signals of melamine at the electrode surface. Furthermore, the melamine adsorbed poly GE surface has been studied using atomic force microscopy (AFM). Poly GE successfully detects the oxidation signals of melamine in the linear range of 0.05-1.31 ppm in laboratory samples. The proposed poly GE successfully detects the melamine signal (0.06-0.85 ppm) in tainted milk powder samples. It also exhibits two well-separated anodic oxidation peaks for urine and melamine in melamine-spiked human urine samples. Gas chromatography-mass spectrometry (GC-MS) was also employed for the successful detection of melamine in the above proposed real samples.
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Affiliation(s)
- Tsung-Hsuan Tsai
- Electroanalysis and Bioelectrochemistry Laboratory, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, Taipei, Taiwan, Republic of China
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50
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Jensen S, Früchtl H, Baddeley CJ. Coupling of triamines with diisocyanates on Au(111) leads to the formation of polyurea networks. J Am Chem Soc 2010; 131:16706-13. [PMID: 19883047 DOI: 10.1021/ja9043032] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The surface-confined coupling reaction between melamine (1,3,5-triazine-2,4,6-triamine) and 1,4-phenylene diisocyanate has been investigated on Au(111) by scanning tunneling microscopy. Diisocyanate species are stabilized at the edges of melamine arrays and coupling reactions to form small urea oligomers may be initiated at room temperature. These oligomers are incorporated into the two-dimensional melamine array. Annealing accelerates the formation of larger oligomers with multiple urea linkages. The oligomers can themselves form ordered 2-D structures stabilized by intermolecular H-bonding. At higher annealing temperatures, oligomers containing as many as seven or eight urea linkages were identified. These oligomers were able to form 2-D porous structures via interoligomer H-bonding interactions. We discuss the composition of all of the phases observed and identify how covalent and noncovalent interactions stabilize each phase.
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Affiliation(s)
- Sean Jensen
- EaStCHEM School of Chemistry, University of St Andrews, North Haugh, St Andrews, Fife, KY16 9ST, United Kingdom
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