Abstract
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...
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
