title: From Metal Thiobenzoates to Metal Sulfide Nanocrystals: An Experimental and Theoretical Investigation.
abstract: 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, Cu2-xS, 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.
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. zhihua.zhang@ap.rhodia.com.
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. peipeigy@yahoo.com.sg.
authors.forename: Wen Pei
authors.initials: WP
authors.lastname: Lim
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. wongct@ihpc.a-star.edu.sg.
authors.forename: Chiong Teck
authors.initials: CT
authors.lastname: Wong
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. chmxhr@nus.edu.sg.
authors.forename: Hairuo
authors.initials: H
authors.lastname: Xu
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. fenfang.yin@ap.rhodia.com.
authors.forename: Fenfang
authors.initials: F
authors.lastname: Yin
authors.affiliation: Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore. chmcws@nus.edu.sg.
authors.forename: Wee Shong
authors.initials: WS
authors.lastname: Chin
keywords: cadmium sulfide; copper sulfide; indium sulfide; metal sulfide nanoparticles; silver sulfide; thiobenzoates