Copper, polysulfide complexes

The nse of polysnlfide complexes in catalysis has been discnssed. Two major classes of reactions are apparent (1) hydrogen activation and (2) electron transfers. For example, [CpMo(S)(SH)]2 catalyzes the conversion of nitrobenzene to aniline at room temperature, while (CpMo(S))2S2CH2 catalyzes a number of reactions snch as the conversion of bromoethylbenzene to ethylbenzene and the rednction of acetyl chloride, as well as the rednction of alkynes to the corresponding cw-alkenes. Electron transfer reactions see Electron Transfer in Coordination Compounds) have been studied because of their relevance to biological processes (in, for example, ferrodoxins), and these cluster compounds are dealt with in Iron-Sulfur Proteins. Other studies include the use of metal polysulfide complexes as catalysts for the photolytic reduction of water by THF and copper compounds for the hydration of acetylene to acetaldehyde. ... 

Regarding the chemical nature of species in LB films, XPS has been used to identify mixed sulfide/polysulfides in nonstoichiometric sulfides of copper (9,19), elemental Se in CdAr films exposed to H2Se (75), and the nature of nitrogen-containing species in LB films made from ArH on subphases of amine-complexed metal ions of M2+ [M = Cu (9), Pt, Pd (74)1. The decomposition of PbS in StH acid films has also been investigated by XPS (68,70). Of two XPS studies of HgS formation in FA films (22,45), one was able to demonstrate that the p-HgS form (mefo-cinna-bar) was present. 

Copper(I) Sulfido Anions. There is a remarkable array of polynuclear anions containing sulfur rings or chains that can be isolated as salts of large cations. They are formed by dissolution of copper sulfides in polysulfide solutions or by the action of sulfur and H2S on ethanolic solutions of Cu11 acetate. Examples are ions such as [Cu2S20]4-, [Cu3Si2]3, and [Cu4Si8]4-. Many of the structures are quite complex, for example, (17-H-VII) and (17-H-VIII). 

Treatment of aqueous solutions of copper(II) salts with ammonium polysulfide gives rise to NH4tCuS4] 163), from which other [ 084] salts can he obtained (35, 163, 283). Two thiocarbonato complexes, M[CuCS3] (M = K, NH4), are also known (162). 

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