在水相中通过手性配体直接合成手性魔幻尺寸团簇

Chiral magic-size clusters via direct aqueous synthesis with chiral ligands

尺寸小于2 nm的手性胶体半导体魔尺寸团簇(MSCs)为手性配体提供了丰富的表面结合位点,因此在手性半导体纳米材料应用方面具有巨大潜力.然而,手性MSCs的制备和光学表征却鲜有报道.本研究以手性半胱氨酸为配体,首次在室温水溶液中合成了单组合形式的手性MSCs,其中CdS MSCs在366 nm波长处有独特的尖锐吸收峰,CdSe MSCs在420 nm波长处有独特的尖锐吸收峰.通过改变手性配体的添加量,可以很容易地调节所制备的手性MSCs的光学活性.制备的手性CdS MSCs和CdSe MSCs的最大吸收不对称系数分别达到3.6×10^(−4)和5.6×10^(−4).实验结果表明,制备的MSCs的手性光学特性可能来源于配体诱导MSCs表面的原子重排.本研究不仅提供了制备手性MSCs的方法,而且为手性MSCs的研究和应用开辟了道路.

Chiral colloidal semiconductor magic-sized clusters(MSCs)with dimensions less than 2 nm provide abundant surface binding sites for chiral ligands and thus have great potential for chiral semiconductor nanomaterial applications.However,the preparation and optical characterization of chiral MSCs are rarely reported in the past.In this study,chiral MSCs in a single-ensemble form,containing CdS MSCs with a unique sharp absorption peak at 366 nm and CdSe MSCs at 420 nm,were synthesized for the first time in aqueous solution at room temperature using chiral cysteine as ligands.The optical activity of the prepared chiral MSCs can be easily adjusted by varying the amount of chiral ligands added.The maximum absorption asymmetry factors of the prepared chiral CdS MSCs and CdSe MSCs reach 3.6×10^(−4) and 5.6×10^(−4),respectively.The experiment results indicate that the chiral optical properties of the prepared MSCs may originate from the ligand-induced atomic rearrangement on the surface of MSCs.This study not only provides a general method for obtaining chiral MSCs,but also opens the way for research and applications of chiral MSCs.