Zhu Weijun, Lin Zhuohan, Zhang Xue, Wang Wei, Li Yan
Key Laboratory for Advanced Materials, Shanghai Key Laboratory of Functional Materials Chemistry, School of Chemistry and Molecular Engineering, East China University of Science and Technology, Shanghai 200237, China.
Nanoscale. 2022 Aug 11;14(31):11210-11217. doi: 10.1039/d2nr02399g.
Magic-size clusters (MSCs) are molecular materials with unique properties at the border between molecules and solids, providing important insights into the nanocrystal formation process. However, the synthesis of multicomponent alloy MSCs in a single-ensemble form remains challenging due to their tiny size and difficult doping control. Herein, for the first time, we successfully synthesized alloy ZnCdSe MSCs ( = 1-12) with a unique sharp absorption peak at 352 nm by cation exchange between Cd ions and pre-synthesized (ZnSe) MSCs in a diamine solution at room temperature. The experimental results show that the use of diamines is crucial to the formation of stable ZnCdSe MSCs, which may be attributed to two amine groups that can coordinate to the surface of MSCs simultaneously. Limited by the robust interaction between diamine ligands and MSCs, the partial cation exchange results in the formation of alloy ZnCdSe MSCs. In contrast, complete cation exchange occurs in a monoamine solution, giving (CdSe) MSCs. Besides, a lower reaction temperature and a higher concentration of diamine favor the formation of ZnCdSe MSCs. Our study provides an important basis for further understanding of the transformation of MSCs and a new approach to the controllable synthesis of alloyed MSCs.
魔尺寸团簇（MSCs）是在分子与固体边界具有独特性质的分子材料，为纳米晶体形成过程提供了重要见解。然而，以单一聚集体形式合成多组分合金MSCs仍然具有挑战性，因为它们尺寸微小且掺杂控制困难。在此，我们首次在室温下于二胺溶液中通过镉离子与预先合成的（ZnSe）MSCs之间的阳离子交换，成功合成了在352nm处具有独特尖锐吸收峰的合金ZnCdSe MSCs（=1 - 12）。实验结果表明，二胺的使用对于稳定的ZnCdSe MSCs的形成至关重要，这可能归因于两个胺基可同时与MSCs表面配位。受二胺配体与MSCs之间强相互作用的限制，部分阳离子交换导致合金ZnCdSe MSCs的形成。相比之下，在单胺溶液中发生完全阳离子交换，生成（CdSe）MSCs。此外，较低的反应温度和较高浓度的二胺有利于ZnCdSe MSCs的形成。我们的研究为进一步理解MSCs的转变提供了重要依据，并为合金化MSCs的可控合成提供了新方法。
