C–H···O Hydrogen Bonding in Pentamers of Isatin
| Autor: | David A. Turner, S. Alex Kandel, Angela M. Silski, Steven A. Corcelli, Joseph M. Coman, John C. Poutsma, Jacob P. Petersen, Zach M. Smith, Ryan D. Brown |
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| Rok vydání: | 2017 |
| Předmět: |
Hydrogen
Hydrogen bond Pentamer Isatin Dimer chemistry.chemical_element 02 engineering and technology 010402 general chemistry 021001 nanoscience & nanotechnology Photochemistry 01 natural sciences 0104 chemical sciences Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry.chemical_compound Crystallography General Energy chemistry Monolayer Molecule Physical and Theoretical Chemistry 0210 nano-technology Methyl group |
| Zdroj: | The Journal of Physical Chemistry C. 121:21520-21526 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/acs.jpcc.7b07444 |
| Popis: | Self-assembled monolayers of 1H-indole-2,3-dione (isatin), 3-methyl 2-oxindole, and 7-fluoroisatin are observed on the Au(111) surface via scanning tunneling microscopy (STM). We observed that isatin forms pentamers with density functional theory providing support for a cyclic structure stabilized by both N–H···O and C–H···O hydrogen bonds between neighboring molecules. The C–H···O bond is made between the 7-position C–H acting as the hydrogen bond donor and the 3-position carbonyl as the hydrogen bond acceptor, and calculations show that the isatin pentamer structure is 12 kJ/mol more stable than the dimer. When the 3-position carbonyl is removed and replaced with a methyl group (3-methyl 2-oxindole), we observe a monolayer with a mixture of catemer chains and pentameric clusters that are qualitatively different from those of isatin. Pentamer formation is completely broken when the 7-position hydrogen is removed and replaced with fluorine; the monolayer of 7-fluoroisatin is composed of a mixture of close... |
| Databáze: | OpenAIRE |
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