Horita Yusuke, Hossain Sakiat, Ishimi Mai, Zhao Pei, Sera Miyu, Kawawaki Tokuhisa, Takano Shinjiro, Niihori Yoshiki, Nakamura Toshikazu, Tsukuda Tatsuya, Ehara Masahiro, Negishi Yuichi
Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
Research Institute for Science & Technology, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan.
J Am Chem Soc. 2023 Nov 1;145(43):23533-23540. doi: 10.1021/jacs.3c07194. Epub 2023 Oct 20.
Electronic structures of anion-templated silver nanoclusters (Ag NCs) are not well understood compared to conventional, template-free Ag NCs. In this study, we synthesized three new anion-templated Ag NCs, namely [S@Ag(S-4CBM)(PPh)], [S@Ag(S-4CBM)(PPh)], and [Cl@Ag(S-4CBM)(PPh)][PPh], where S-4CBM = 4-chlorobenzene methanethiolate, and single-crystal X-ray crystallography revealed that they have S@Ag, S@Ag, and Cl@Ag cores, respectively. Investigation of their electronic structures by optical spectroscopy and theoretical calculations elucidated the following unique features: (1) their electronic structures are different from those of template-free Ag NCs described by the superatomic concept; (2) optical absorption in the range of 550-400 nm for S-templated Ag NCs is attributed to the charge transitions from S-templated Ag-cage orbitals to the s-shaped orbital in the S moiety; (3) the Cl-templated Ag NCs can be viewed as [Cl@Ag(S-4CBM)(PPh)][PPh] rather than the ion pair [Cl@Ag(S-4CBM)(PPh)][PPh]; and (4) singlet-coupled singly occupied orbitals are involved in the optical absorption of the Cl-templated Ag NC.
与传统的无模板银纳米团簇（Ag NCs）相比，阴离子模板化银纳米团簇的电子结构尚未得到很好的理解。在本研究中，我们合成了三种新的阴离子模板化Ag NCs，即[S@Ag(S - 4CBM)(PPh)]、[S@Ag(S - 4CBM)(PPh)]和[Cl@Ag(S - 4CBM)(PPh)][PPh]，其中S - 4CBM = 4 - 氯苯甲硫醇盐，单晶X射线晶体学表明它们分别具有S@Ag、S@Ag和Cl@Ag核。通过光谱学和理论计算对其电子结构进行研究，揭示了以下独特特征：（1）它们的电子结构与由超原子概念描述的无模板Ag NCs不同；（2）S模板化Ag NCs在550 - 400 nm范围内的光吸收归因于从S模板化Ag笼轨道到S部分中s形轨道的电荷跃迁；（3）Cl模板化Ag NCs可被视为[Cl@Ag(S - 4CBM)(PPh)][PPh]，而不是离子对[Cl@Ag(S - 4CBM)(PPh)][PPh]；（4）单重态耦合的单占据轨道参与了Cl模板化Ag NC的光吸收。
