Kumara Chanaka, Hoque M Mozammel, Zuo Xiaobing, Cullen David A, Whetten Robert L, Dass Amala
Department of Chemistry & Biochemistry , University of Mississippi , Oxford , Mississippi 38677 , United States.
Department of Physics & Astronomy , University of Texas , San Antonio , Texas 78249 , United States.
J Phys Chem Lett. 2018 Dec 6;9(23):6825-6832. doi: 10.1021/acs.jpclett.8b02993. Epub 2018 Nov 19.
Disclosed herein is a method to obtain the ∼300 kDa gold-hexanethiolate compound, extracted from the Faradaurate series of smaller (3) and larger (1) homologues, thereby permitting the first measurement of its distinctive properties by methods including mass spectrometry, optical spectroscopy, electron microscopy, X-ray scattering, and diffraction. The results suggest a monocrystalline metallic core (free of twinning planes) of ∼3.1 nm minimum dimension, which supports a clear plasmonic optical response, along with a diffuse exterior shell. An idealized model to account for this (and smaller) members of the series is proposed based on the completion of a convex core of regular truncated-octahedral (TO) morphology, that is, the TO (5,5) crystallite comprising 1289 sites. The diffuse layer may comprise the 240 S sites (thiolate sulfur headgroups) and 96 Au-adatom sites, giving a total composition (1385,240) and a molar mass of ∼301.0 kDa (90.7% Au). The ∼300 and ∼400 kDa gold compounds contain Au and Au atoms, respectively.
本文公开了一种从法拉达酸盐系列较小（3）和较大（1）同系物中提取约300 kDa金己硫醇盐化合物的方法，从而能够通过包括质谱、光谱学、电子显微镜、X射线散射和衍射等方法首次测量其独特性质。结果表明，存在一个最小尺寸约为3.1 nm的单晶金属核（无孪晶面），其支持清晰的等离子体光学响应，以及一个弥散的外壳。基于具有规则截顶八面体（TO）形态的凸核的完成，提出了一个理想化模型来解释该系列的这一（以及较小的）成员，即由1289个位点组成的TO（5,5）微晶。弥散层可能包含240个S位点（硫醇盐硫头基）和96个金吸附原子位点，给出总组成（1385,240）和摩尔质量约为301.0 kDa（90.7%金）。约300 kDa和约400 kDa的金化合物分别含有金原子和金原子。
