title: Effect of functional group (fluorine) of aromatic thiols on electron transfer at the molecule-metal interface.
abstract: Electron transfer at the molecule-metal interface of self-assembled monolayers of 1,1';4',1''-terphenyl-4''-thiol (BBB) and its partially fluorinated counterpart (BFF: p-thiophenyl-nonafluorobiphenyl) on Au(111) is investigated by core-hole clock spectroscopy. Ultrafast electron transfer at the BBB/Au(111) interface in the low-femtosecond regime (on the same time scale as the C 1s core-hole lifetime, approximately 6 fs) was observed. In contrast, for BFF/Au(111), the interface electron transfer was forbidden during the core-hole decay. This strongly suggests that fluorination of phenyl rings significantly enhances the localization of the excited electrons in the LUMO.
authors.affiliation: Department of Physics, National University of Singapore, 2 Science Drive 3, Singapore 117542, Singapore.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.forename: Li
authors.initials: L
authors.lastname: Wang
authors.forename: Chun
authors.initials: C
authors.lastname: Huang
authors.forename: Ting Ting
authors.initials: TT
authors.lastname: Lin
authors.forename: Xing Yu
authors.initials: XY
authors.lastname: Gao
authors.forename: Kian Ping
authors.initials: KP
authors.lastname: Loh
authors.forename: Zhi Kuan
authors.initials: ZK
authors.lastname: Chen
authors.forename: Andrew Thye Shen
authors.initials: AT
authors.lastname: Wee