Science Institute, University of Iceland, Dunhagi 3, 107 Reykjavik, Iceland.
Chemical Science and Technology Laboratory, Physical Sciences Division, SRI International, 333 Ravenswood Avenue, Menlo Park, California 94025, United States.
Inorg Chem. 2020 Jun 1;59(11):7644-7656. doi: 10.1021/acs.inorgchem.0c00608. Epub 2020 May 13.
Removal of cyanide as nontoxic thiocyanate under physiological conditions may serve as a catalytic detoxification route . Aqueous catalytic reaction conditions were explored where at the conditions employed the reaction proceeded to exhaustion in 1 h. The complex, -[MoO(μ-S)(S)(DMF)] , participates in a ligand exchange reaction of the dimethylformamide ligands and cyanide. Simultaneous sulfur abstraction reaction from the terminal disulfide group forms thiocyanate and terminal sulfido ligand. Respective reaction rates for the two reactions appear competitive where different products were isolated solely based on change of reaction temperature. The approach to determine the number of cyanide ligands participating in the ligand exchange reaction by varying the stoichiometry and reaction temperature led to identification and isolation of tetranuclear complexes and and dinuclear complexes , , and . A synthesized and fully characterized thiocyanate analog of () supports spectroscopic characterization of . The tetranuclear anion, [MoO(μ-S)(CN)], , was crystallized from a reaction at ambient temperature. The dinuclear anion, [MoO(μ-S)(S)(CN)], , was crystallized from similar reaction conditions at lower temperature. The reaction yield of thiocyanate obtained at pH of 7.4 and at 9.2 as a function of time, for several ratios of cyanide, favors the sulfur abstraction reaction at elevated pH. The sulfur abstraction reaction is the first step in a proposed mechanism of the reaction of cyanide and thiosulfate to form thiocyanate and sulfite by .
在生理条件下，将氰化物无毒转化为硫氰酸盐可能是一种催化解毒途径。本文探索了水相催化反应条件，在实验采用的条件下，反应在 1 小时内进行完全。该配合物-[MoO(μ-S)(S)(DMF)]参与二甲基甲酰胺配体与氰化物的配体交换反应。同时，从末端二硫基团中提取硫原子形成硫氰酸盐和末端硫代配体。两个反应的相应反应速率似乎是竞争的，仅根据反应温度的变化就可以分离出不同的产物。通过改变化学计量和反应温度来确定参与配体交换反应的氰化物配体数的方法，导致了四核配合物[MoO(μ-S)(CN)]4-和[MoO(μ-S)(S)(CN)]2-的鉴定和分离，以及双核配合物[MoO(μ-S)(S)L]2+（L = DMF、Py）的鉴定和分离。配合物()的合成和全谱学表征支持了对其的光谱学特征研究。在环境温度下，从反应中结晶出四核阴离子[MoO(μ-S)(CN)]4-。在较低温度下，从类似的反应条件下结晶出双核阴离子[MoO(μ-S)(S)(CN)]2-。在 pH 值为 7.4 和 9.2 时，作为时间的函数，氰化物与硫代硫酸盐反应生成硫氰酸盐和亚硫酸盐的反应收率随时间的增加而增加，这有利于在较高 pH 值下发生硫原子提取反应。硫原子提取反应是氰化物和硫代硫酸盐反应生成硫氰酸盐和亚硫酸盐的提议机制的第一步。
