Zhang Zhihua, Lim Wen Pei, Wong Chiong Teck, Xu Hairuo, Yin Fenfang, Chin Wee Shong
Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore.
Nanomaterials (Basel). 2012 Apr 3;2(2):113-133. doi: 10.3390/nano2020113.
A simple preparation of metal sulfide nanoparticles via the decomposition of thiobenzoate precursors at room temperature is presented and discussed. Long chain alkylamines were found to mediate the breakdown of metal thiobenzoates, such as those containing Ag, Cu, In and Cd, to produce uniform Ag₂S, CuS, In₂S₃ and CdS nanoparticles respectively. The long chain amines are assumed to play dual roles as the nucleophilic reagent and the capping agent. It was found that sizes of the nanoparticles can be controlled by changing the type of amine used, as well as the molar ratio between amine and the precursor. We performed DFT calculations on a proposed mechanism involving an initial nucleophilic addition of amine molecule onto the thiocarboxylates. The proposed reaction was also confirmed through the analysis of by-products via infrared spectroscopy. On the basis of this understanding, we propose to manipulate the stability of the precursors by coordination with suitable stabilizing groups, such that the reaction kinetics can be modified to generate different nanostructures of interest.
本文介绍并讨论了一种通过硫代苯甲酸酯前体在室温下分解来简单制备金属硫化物纳米颗粒的方法。研究发现，长链烷基胺可介导金属硫代苯甲酸酯（如含银、铜、铟和镉的金属硫代苯甲酸酯）的分解，分别生成均匀的硫化银、硫化铜、硫化铟和硫化镉纳米颗粒。长链胺被认为同时起到亲核试剂和封端剂的双重作用。研究发现，通过改变所用胺的类型以及胺与前体之间的摩尔比，可以控制纳米颗粒的尺寸。我们对一种涉及胺分子初始亲核加成到硫代羧酸盐上的 proposed 机制进行了密度泛函理论（DFT）计算。通过红外光谱对副产物的分析也证实了 proposed 反应。基于这种认识，我们建议通过与合适的稳定基团配位来操纵前体的稳定性，从而可以改变反应动力学以生成不同的目标纳米结构。
