Beyond thiols, beyond gold: Novel NHC-stabilized nanoclusters in catalysis

超越硫醇，超越金：催化中新型 NHC 稳定纳米团簇

基本信息

批准号：
21H01949
负责人：
CRUDDEN Cathleen
金额：
$ 11.23万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2021
资助国家：
日本
起止时间：
2021-04-01 至 2025-03-31
项目状态：
未结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-21H01949/
关键词：
nanocluster gold N-heterocyclic carbene catalysis chirality chiral C-H oxidation

项目摘要

In FY 2022, we successfully synthesized gold nanoclusters stabilized by N-heterocyclic carbene (NHC) ligands in collaboration with the Tsukuda and Hakkinen group. We demonstrated that the use of chiral, BIANP-inspired NHCs to prepare chiral Au10 nanoclusters with a unique elongated central Au10 core. ESI-MS and single-crystal X-ray crystallography confirmed the molecular formula to be [Au10(bisNHC)4Br2]2+. The chiral Au10 nanocluster adopts a linear edge-shared tetrahedral geometry with a prolate shape. The UV-vis spectrum this cluster in CH2Cl2 displayed four prominent absorption bands at 291, 325, and 546 nm, which is a significant departure from the spectra of bis-NHC dinuclear Au(I) complexes. CD spectra demonstrate chirality transfer from the chiral bisNHC ligand to the inner Au10 nanocluster core. The reaction monitoring by ESI-MS and UV-vis spectroscopy indicated the formation of [Au9(bisNHC)4Br]2+ as a key intermediate.In addition, we achieved the synthesis of a toroidal Au10 cluster stabilized by NHC bearing bulky 2,4,6-trimethylbenzyl units. The [Au10(NHC)6Br3]Br cluster readily undergoes conversion to form a biicosahedral Au25 cluster, while the corresponding Cl cluster showed no conversion. This facyt may be explained both by the steric environment imposed by the bulky mesityl-substituted NHC ligand, as well as steric and electronic factors introduced by the smaller chloride ligands.

在2022财年，我们成功合成了与Tsukuda和Hakkinen Group合作，由N-杂环卡宾（NHC）配体稳定的金纳米簇稳定。我们证明了使用手性BIANP启发的NHC来制备具有独特的细长中央Au10核心手性Au10纳米簇。 ESI-MS和单晶X射线晶体学证实了分子公式为[AU10（BISNHC）4BR2] 2+。手性Au10纳米群采用带状形状的线性边缘共享的四面体几何形状。 CH2CL2中的UV-VIS光谱在291、325和546 nm处显示了四个突出的吸收带，这与Bis-NHC Dinuclear Au（I）复合物的光谱显着偏离。 CD光谱表明手性从手性BISNHC配体转移到内部Au10纳米簇核心。 ESI-MS和UV-VIS光谱法监测的反应监测表明，形成了[Au9（BisnHC）4BR] 2+作为关键中间体的形成。此外，我们实现了由NHC携带的NHC稳定稳定的环形Au10的合成。 [AU10（NHC）6BR3] BR簇很容易进行转换以形成生物面向AU25簇，而相应的CL簇没有显示转换。较大的氯化物配体引入的空间和电子因素所施加的空间环境可以解释这种面孔。