title: A critical size for emergence of nonbulk electronic and geometric structures in dodecanethiolate-protected Au clusters.
abstract: We report on how the transition from the bulk structure to the cluster-specific structure occurs in n-dodecanethiolate-protected gold clusters, Au(n)(SC12)m. To elucidate this transition, we isolated a series of Au(n)(SC12)m in the n range from 38 to ∼520, containing five newly identified or newly isolated clusters, Au104(SC12)45, Au(∼226)(SC12)(∼76), Au(∼253)(SC12)(∼90), Au(∼356)(SC12)(∼112), and Au(∼520)(SC12)(∼130), using reverse-phase high-performance liquid chromatography. Low-temperature optical absorption spectroscopy, powder X-ray diffractometry, and density functional theory (DFT) calculations revealed that the Au cores of Au144(SC12)60 and smaller clusters have molecular-like electronic structures and non-fcc geometric structures, whereas the structures of the Au cores of larger clusters resemble those of the bulk gold. A new structure model is proposed for Au104(SC12)45 based on combined approach between experiments and DFT calculations.
authors.affiliation: Department of Applied Chemistry, Faculty of Science, Tokyo University of Science , 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Negishi
authors.forename: Tafu
authors.initials: T
authors.lastname: Nakazaki
authors.forename: Sami
authors.initials: S
authors.lastname: Malola
authors.forename: Shinjiro
authors.initials: S
authors.lastname: Takano
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Niihori
authors.forename: Wataru
authors.initials: W
authors.lastname: Kurashige
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamazoe
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Tsukuda
authors.forename: Hannu
authors.initials: H
authors.lastname: Häkkinen