Size and Structure Dependence of Electronic States in Thiolate-Protected Gold Nanoclusters of Au25(SR)18, Au38(SR)24, and Au144(SR)60

详细信息    查看全文

• 作者：Tsutomu Ohta ; Masahiro Shibuta ; Hironori Tsunoyama ; Yuichi Negishi ; Toyoaki Eguchi ; Atsushi Nakajima
• 刊名：The Journal of Physical Chemistry C
• 出版年：2013
• 出版时间：February 21, 2013
• 年：2013
• 卷：117
• 期：7
• 页码：3674-3679
• 全文大小：349K
• 年卷期：v.117,no.7(February 21, 2013)
• ISSN：1932-7455

文摘

The electronic states of three different sizes of compositionally precise thiolate-protected gold nanoclusters, Au₂₅(SR)₁₈, Au₃₈(SR)₂₄, and Au₁₄₄(SR)₆₀ (R = C₁₂H₂₅), have been evaluated by X-ray photoemission spectroscopy. The Au 4f core-levels of the nanoclusters are well reproduced by two spectral components derived from centered core-Au and positively charged shell-Au atoms, the numbers of which are determined based on the atomic structures of the nanoclusters. The spin鈥搊rbit splitting of Au 5d_5/2 and 5d_3/2 in the valence band becomes narrower than that for bulk Au, depending on the cluster size, which is quantitatively characterized by a reduction in the average coordination number of Au. The Au 5d valence-band spectra also show that the charge reorganization of 5d electrons induced by interaction with thiol molecules is more significant for the 5d_5/2 than the 5d_3/2 orbital.