A critical size for emergence of nonbulk electronic and geometric structures in dodecanethiolate-protected Au clusters

Yuichi Negishi; Tafu Nakazaki; Sami Malola; Shinjiro Takano; Yoshiki Niihori; Wataru Kurashige; Seiji Yamazoe; Tatsuya Tsukuda; Hannu Häkkinen

doi:10.1021/ja5109968

A critical size for emergence of nonbulk electronic and geometric structures in dodecanethiolate-protected Au clusters

J Am Chem Soc. 2015 Jan 28;137(3):1206-12. doi: 10.1021/ja5109968. Epub 2015 Jan 14.

Authors

Yuichi Negishi¹, Tafu Nakazaki, Sami Malola, Shinjiro Takano, Yoshiki Niihori, Wataru Kurashige, Seiji Yamazoe, Tatsuya Tsukuda, Hannu Häkkinen

Affiliation

¹ Department of Applied Chemistry, Faculty of Science, Tokyo University of Science , 1-3 Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.

PMID: 25549276
DOI: 10.1021/ja5109968

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.