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Li Z, Li Y, Yin C. Manipulating Molecular Self-Assembly Process at the Solid-Liquid Interface Probed by Scanning Tunneling Microscopy. Polymers (Basel) 2023; 15:4176. [PMID: 37896420 PMCID: PMC10610993 DOI: 10.3390/polym15204176] [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: 09/07/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/29/2023] Open
Abstract
The phenomenon of ordered self-assembly on solid substrates is a topic of interest in both fundamental surface science research and its applications in nanotechnology. The regulation and control of two-dimensional (2D) self-assembled supra-molecular structures on surfaces have been realized through applying external stimuli. By utilizing scanning tunneling microscopy (STM), researchers can investigate the detailed phase transition process of self-assembled monolayers (SAMs), providing insight into the interplay between intermolecular weak interactions and substrate-molecule interactions, which govern the formation of molecular self-assembly. This review will discuss the structural transition of self-assembly probed by STM in response to external stimuli and provide state-of-the-art methods such as tip-induced confinement for the alignment of SAM domains and selective chirality. Finally, we discuss the challenges and opportunities in the field of self-assembly and STM.
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Affiliation(s)
| | - Yanan Li
- School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China;
| | - Chengjie Yin
- School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China;
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Liu S, Norikane Y, Kikkawa Y. Two-dimensional molecular networks at the solid/liquid interface and the role of alkyl chains in their building blocks. BEILSTEIN JOURNAL OF NANOTECHNOLOGY 2023; 14:872-892. [PMID: 37674543 PMCID: PMC10477993 DOI: 10.3762/bjnano.14.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 07/25/2023] [Indexed: 09/08/2023]
Abstract
Nanoarchitectonics has attracted increasing attention owing to its potential applications in nanomachines, nanoelectronics, catalysis, and nanopatterning, which can contribute to overcoming global problems related to energy and environment, among others. However, the fabrication of ordered nanoarchitectures remains a challenge, even in two dimensions. Therefore, a deeper understanding of the self-assembly processes and substantial factors for building ordered structures is critical for tailoring flexible and desirable nanoarchitectures. Scanning tunneling microscopy is a powerful tool for revealing the molecular conformations, arrangements, and orientations of two-dimensional (2D) networks on surfaces. The fabrication of 2D assemblies involves non-covalent interactions that play a significant role in the molecular arrangement and orientation. Among the non-covalent interactions, dispersion interactions that derive from alkyl chain units are believed to be weak. However, alkyl chains play an important role in the adsorption onto substrates, as well as in the in-plane intermolecular interactions. In this review, we focus on the role of alkyl chains in the formation of ordered 2D assemblies at the solid/liquid interface. The alkyl chain effects on the 2D assemblies are introduced together with examples documented in the past decades.
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Affiliation(s)
- Suyi Liu
- Graduate School of Science and Technology, University of Tsukuba, Ibaraki, 305-8571, Japan
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
| | - Yasuo Norikane
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
- Faculty of Pure and Applied Sciences, University of Tsukuba, Ibaraki, 305-8571, Japan
| | - Yoshihiro Kikkawa
- National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan
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Hu Y, Lee SL, Deng W. Odd-Even Effect on Supramolecular Co-Assemblies: Control over the Two-Dimensional Self-Assemblies of a Fluorenone Derivative with Asymmetrically Substituted Alkyl Chains. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022; 38:1757-1765. [PMID: 35084866 DOI: 10.1021/acs.langmuir.1c02866] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The precise control of two-dimensional supramolecular co-assemblies presents a research topic related to advance nanotechnology. Here, we report a scanning tunneling microscopy (STM) study of the mixture behavior of three fluorenone derivatives at the liquid-solid interface. The target molecule is F-C12C13 whose structure bears asymmetrical alkyls, whereas the regulating molecules, either F-C12C12 or F-C13C13, are structurally symmetric. By STM imaging of systematic mixtures with various volumes among the sample solutions, we found that the mixing ratio mainly determined the binary outcomes. Compared with F-C12C12, F-C13C13 shows a stronger ability to dominate the patterning, explained by the larger binding and adsorption energies calculated by the force field simulations. Moreover, the odd-even effect exists in the system. Overall, we acquired knowledge about the regulating ability of bi-component supramolecular assembling, especially for structurally asymmetric molecular systems.
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Affiliation(s)
- Yi Hu
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Shern-Long Lee
- Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China
| | - Wenli Deng
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China
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Maranda-Niedbała A, Krzyżewska K, Kotwica K, Skórka Ł, Drapała J, Jarzembska KN, Zagórska M, Proń A, Nowakowski R. 9,10-Anthraquinones Disubstituted with Linear Alkoxy Groups: Spectroscopy, Electrochemistry, and Peculiarities of Their 2D and 3D Supramolecular Organizations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:15048-15063. [PMID: 33271019 PMCID: PMC7745534 DOI: 10.1021/acs.langmuir.0c02586] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 11/20/2020] [Indexed: 06/12/2023]
Abstract
Spectroscopic, electrochemical, and structural properties of 2,6-dialkoxy-9,10-anthraquinones (Anth-OCn, n = 4, 6, 8, 10, and 12) of increasing alkoxy substituents length were investigated. UV-vis spectroscopy showed a substitution-induced bathochromic shift of the least energetic band from 325 nm in the case of unsubstituted anthraquinone to ca. 350 nm for the studied derivatives. Similarly as unsubstituted anthraquinone, the studied compound showed two reversible one electron reductions to a radical anion and spinless anions, respectively. The first reduction was affected by electron-donating properties of the substituents, its potential being shifted to ca. -1.5 V (vs Fc/Fc+), i.e., by 80 to 95 mV as compared to the case of unsubstituted anthraquinone. This corresponded to a decrease of |EA| from 3.27 to 3.19-3.17 eV. The experimental spectroscopic and electrochemical data were in full agreement with the DFT calculations. The introduction of the alkoxy substituent improved solution processibility of the studied compounds and facilitated the formation of their ordered supramolecular 2D aggregation on HOPG as well as single crystal growth from solutions. Comparative structural investigations carried out on single crystals and monolayers deposited on HOPG revealed two, mutually related, effects of the substituent length on the resulting supramolecular organization. The first one concerns both the 2D organization in the monolayers and 3D molecular arrangement in crystals: increasing substituent length evolution of the structure occurs from herringbone-type to lamellar. The second effect, observed in monolayers of the derivatives with longer substituents, concerns gradual evolution of their lamellar structures with increasing substituent length. This evolution is induced by the structure of the graphite substrate and involves increasing correlation of the molecules orientation (anthraquinone cores as well as alkoxy substituents) with the symmetry of the graphite substrate. As a result, their 2D and 3D structures become dissimilar.
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Affiliation(s)
| | - Klaudyna Krzyżewska
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
| | - Kamil Kotwica
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
- Warsaw
University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warszawa, Poland
| | - Łukasz Skórka
- Warsaw
University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warszawa, Poland
| | - Jakub Drapała
- Warsaw
University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warszawa, Poland
- University
of Warsaw, Department of Chemistry, Żwirki i Wigury 101, 02-089 Warszawa, Poland
| | | | - Małgorzata Zagórska
- Warsaw
University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warszawa, Poland
| | - Adam Proń
- Warsaw
University of Technology, Faculty of Chemistry, Noakowskiego 3, 00-664 Warszawa, Poland
| | - Robert Nowakowski
- Institute
of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warszawa, Poland
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Qin Y, Yang Y, Wang Y, Wang X, Yao M. Theoretical study of the substrate and molecular density effects on molecular self-assembly. NEW J CHEM 2019. [DOI: 10.1039/c9nj04506f] [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
This work is aiming at theoretically exploring the substrate and molecular density effects on molecular self-assembly.
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Affiliation(s)
- Yuan Qin
- School of Materials Science and Engineering
- Dalian University of Technology
- Dalian 116024
- China
| | - Yingying Yang
- School of Materials Science and Engineering
- Dalian University of Technology
- Dalian 116024
- China
| | - Yuelin Wang
- School of Materials Science and Engineering
- Dalian University of Technology
- Dalian 116024
- China
| | - Xudong Wang
- School of Materials Science and Engineering
- Dalian University of Technology
- Dalian 116024
- China
| | - Man Yao
- School of Materials Science and Engineering
- Dalian University of Technology
- Dalian 116024
- China
- Key Laboratory of Energy Materials and Devices
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Hu Y, Xu S, Miao K, Miao X, Deng W. Same building block, but diverse surface-confined self-assemblies: solvent and concentration effects-induced structural diversity towards chirality and achirality. Phys Chem Chem Phys 2018; 20:17367-17379. [PMID: 29905343 DOI: 10.1039/c8cp01308j] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Fabricating complex nano-networks on solid substrates is a research area that has attracted much attention in the field of molecular self-assembly. By designing a fluorenone derivative of 2-heptyloxy-7-pentadecyloxy-9-fluorenone (HPF), we obtained a surface-confined system that presented diverse nanostructures. The assembled networks for HPF were highly dependent on the solvent and concentration. At the liquid/solid interface, chiral tetramer-S, hexamer-S, and tetramer-linear structures as well as achiral irregular-linear and random structures were recorded. On the dry surface, we observed chiral octamer-S and achiral alternate configurations. During the self-assembly process, the short and long alkyl chains of HPF showed selective identification, which contributed to the formation of S-like or anti-S-like tetramers, hexamers and octamers, resulting in chiral structures. The nanopatterns were stabilized under the driving forces of dipolar interactions, hydrogen bonds and van der Waals interactions. Moreover, we performed forcefield calculations in order to further understand the underlying mechanisms from the viewpoints of their force strengths and binding energies. In general, the present work provides a significant impetus to induce polymorphous structures, and we believe that it will promote the study of chirality and achirality in the field of molecular self-assembly.
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Affiliation(s)
- Yi Hu
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
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Hu Y, Miao K, Xu L, Zha B, Long M, Miao X, Deng W. Two side chains, three supramolecules: exploration of fluorenone derivatives towards crystal engineering. Phys Chem Chem Phys 2017; 19:19205-19216. [PMID: 28702598 DOI: 10.1039/c7cp03894a] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Structural diversity obtained through two-dimensional molecular self-assembly induced by the chain length effect has gained immense attention, not only because of its significance in crystal engineering but also for its potential application in nanoscience and nanotechnology. Three kinds of fluorenone derivative, named F-C7C7, F-C14C7, and F-C14C14, were synthesized and used for systematic exploration of their crystalline difference. At first, scanning electron microscopy and X-ray powder diffraction were performed to investigate their differences in morphology and three-dimensional crystal structure. Then scanning tunneling microscopy experiments were conducted to compare the self-assembled monolayers. Moreover, different solvents were used to repeatedly investigate the occurrence of structural diversity. F-C7C7 could not self-assemble into a stable monolayer on the graphite surface under ambient conditions due to its weak molecule-substrate interaction. F-C14C7 was observed to self-assemble into twist, plier-like, octamer-curve, and random structures in 1-octanoic acid, 1-phenyloctane, n-tetradecane, and dichloromethane, respectively. However, when the same solvents were used and at similar concentrations, the F-C14C14 molecules were arranged into interval, mixed, linear, and plier-like configurations. These self-assembled nanopatterns formed under the driving forces of dipole-dipole interactions, hydrogen bonds, and chain-chain, molecule-substrate, and molecule-solvent van der Waals interactions. Furthermore, from the viewpoint of thermal analysis, differential scanning calorimetry, as well as polarized optical microscopy, was performed to further elucidate the difference between these three compounds in the solid and liquid crystal states. The present system is believed to provide understanding of how the chain length effect induces different crystalline properties, and to open up the possibility of fabricating diverse self-assembled networks for crystal engineering.
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Affiliation(s)
- Yi Hu
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Kai Miao
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Li Xu
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Bao Zha
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Mengying Long
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Xinrui Miao
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Wenli Deng
- College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China.
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Hu Y, Miao K, Xu L, Zha B, Miao X, Deng W. Effects of alkyl chain number and position on 2D self-assemblies. RSC Adv 2017. [DOI: 10.1039/c7ra05811j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Alkyl chain number and position effects are explored via the fabrication and regulation of 2D self-assemblies at liquid/HOPG interfaces.
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Affiliation(s)
- Yi Hu
- College of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Kai Miao
- College of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Li Xu
- College of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Bao Zha
- College of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Xinrui Miao
- College of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510640
- China
| | - Wenli Deng
- College of Materials Science and Engineering
- South China University of Technology
- Guangzhou 510640
- China
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