title: Intramolecular charge transfer and solvation dynamics of thiolate-protected Au20(SR)16 clusters studied by ultrafast measurement.
abstract: It is accepted that the monolayer ligand shell in monolayer-protected gold nanoclusters (MPCs) plays an important role in stabilizing the metal core structure. Previous reports have shown that the core and shell do not interact chemically, and very few studies investigating the intramolecular charge transfer (ICT) between the core and ligand shell in clusters have been reported. The underlying excited state relaxation mechanisms about the influence of solvents, the optically excited vibration, and the roles of the core and shell in charge transfer remain unknown to a large extent. Here we report a femtosecond transient absorption study of a Au20(SR)16 (R = CH2CH2Ph) cluster in toluene and tetrahydrofuran. The ICT from the outside shell to the inside core upon excitation in Au20(SR)16 is identified. The observed solvation-dependent oscillations in different solvents further confirm the photoinduced ICT formation in Au20(SR)16. The results provide a fundamental understanding of the structure-property relationships about the solvation-dependent core-shell interaction in Au MPCs.
authors.affiliation: The State Key Laboratory of Molecular Reaction Dynamics and Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences , Beijing 100190, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Zhou
authors.forename: Silvije
authors.initials: S
authors.lastname: Vdović
authors.forename: Saran
authors.initials: S
authors.lastname: Long
authors.forename: Manzhou
authors.initials: M
authors.lastname: Zhu
authors.forename: Linyin
authors.initials: L
authors.lastname: Yan
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wang
authors.forename: Yingli
authors.initials: Y
authors.lastname: Niu
authors.forename: Xuefei
authors.initials: X
authors.lastname: Wang
authors.forename: Qianjin
authors.initials: Q
authors.lastname: Guo
authors.forename: Rongchao
authors.initials: R
authors.lastname: Jin
authors.forename: Andong
authors.initials: A
authors.lastname: Xia