Importance of long-term storage for fluorine-substituted aromatic self-assembled monolayers by the example of 4-fluorobenzene-1-thiolate films on Au(111)
By the example of 4-fluorobenzene-1-thiolate (p-FTP) films on Au(111), we show that a long-term post-preparation storage can improve significantly the quality of fluorinated aromatic self-assembled monolayers (SAMs). Whereas the freshly prepared p-FTP films exhibit a polymorphism, with a dominance o...
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| Main Authors: | , , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
January 28, 2019
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| In: |
The journal of physical chemistry. C, Energy, materials, and catalysis
Year: 2019, Volume: 123, Issue: 7, Pages: 4308-4318 |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.8b12030 |
| Online Access: | Verlag, Volltext: https://doi.org/10.1021/acs.jpcc.8b12030
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| Author Notes: | Waleed Azzam, Eric Sauter, Awad A. Alrashdi, Najd Al-Refaie, Michael Rohwerder, Asif Bashir, and Michael Zharnikov |
| Summary: | By the example of 4-fluorobenzene-1-thiolate (p-FTP) films on Au(111), we show that a long-term post-preparation storage can improve significantly the quality of fluorinated aromatic self-assembled monolayers (SAMs). Whereas the freshly prepared p-FTP films exhibit a polymorphism, with a dominance of a disordered phase, the post-preparation storage triggers a gradual phase transition to a single-phase SAM of exceptional quality. This phase is characterized by the commensurate (16 × √3) structure, a molecular footprint of 23.1 Å2, high orientational order, and hardly perceptible borders between individual domains, with sizes exceeding 80 nm. Significantly, the phase transition is accompanied by morphological transformation of the substrate: whereas the freshly prepared films exhibit comparably large Au adatom islands, typical of aromatic SAMs, the long-storage samples rather reveal etch-pits, typical of alkanethiolate SAMs on Au(111), which generally have a high structural order immediately after the preparation. The above results suggest a deep interrelation between the structural order in the SAMs and surface morphology. A further implication is the importance of both thermodynamic and kinetic factors, a delicate interplay of which is presumably responsible for the observed evolution of p-FTP/Au in the present case. |
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| Item Description: | Gesehen am 15.04.2019 |
| Physical Description: | Online Resource |
| ISSN: | 1932-7455 |
| DOI: | 10.1021/acs.jpcc.8b12030 |