Department of Chemistry, Anhui University, Hefei, Anhui, 230026, China.
Small. 2014 Mar 12;10(5):1008-14. doi: 10.1002/smll.201302279. Epub 2013 Oct 24.
Enantioselective synthesis of chiral Au38 nanoclusters is achieved with chiral 2-phenylpropane-1-thiol (abbreviated as R/S-PET, organic soluble), captopril and glutathione (water soluble) as the respective ligand. The circular dichroism (CD) spectra of Au38 (R-PET)24 and Au38 (S-PET)24 show multiple bands which are precisely mirror-imaged, while their normal optical absorption spectra are identical with each other and also superimposable with that of the racemic Au38 (SCH2 CH2 Ph)24 nanoclusters. The observed CD signals are not from the chiral ligands themselves (which only give rise to CD signals in the UV (<250 nm), rather than in the visible wavelength region). Chiral Au38 nanoclusters with different types of ligands are further compared. Although the Au38 core is intrinsically chiral, different chiral ligands are found to largely influence the chiroptical response of the overall nanocluster. Thus, the chiral response of ligand-protected nanoclusters has both contributions from the metal core and the ligand shell around it. These optically active nanoclusters hold promise in future applications such as chiral sensing and catalysis.
手性 Au38 纳米团簇的对映选择性合成是通过手性 2-苯基丙烷-1-硫醇（缩写为 R/S-PET，有机可溶性）、卡托普利和谷胱甘肽（水溶性）作为各自的配体来实现的。Au38（R-PET）24 和 Au38（S-PET）24 的圆二色性（CD）光谱显示出多个精确镜像的谱带，而它们的正常光吸收光谱彼此相同，也与外消旋的 Au38（SCH2CH2Ph）24 纳米团簇的光吸收光谱重叠。观察到的 CD 信号不是来自手性配体本身（它们只在手性 Au38 纳米团簇在紫外光（<250nm）区域产生 CD 信号，而不是在可见光波长区域）。进一步比较了具有不同类型配体的手性 Au38 纳米团簇。虽然 Au38 核本身是手性的，但不同的手性配体被发现对手性纳米团簇的手性响应有很大影响。因此，配体保护的纳米团簇的手性响应既来自金属核，也来自其周围的配体壳。这些光学活性纳米团簇在手性传感和催化等未来应用中具有广阔的应用前景。
