Thiosulphates and Thionates

Thiosulphates and Thionates. A neutron-diffraction study has shown that in barium thiosulphate monohydrate the tetrahedral 8203 anion has the bond lengths S—8=1.979 and 8—0= 1.472-1.483 A the Ba—8 distances are 3.355 and 3.424 A. A crystal structure determination of bis(ethylenethiourea)zinc(ii) thiosulphate has shown that each zinc atom is tetrahedrally surrounded by three sulphur atoms (two from etu and one from the thiosulphate group, with the mean distance Zn—8 = 2.320 A) and one oxygen atom from the 82O3 group. Crystalline Zn(NH3)3(8203),H20 and Cd(NH3)3(8203) have been prepared and characterized spectral data indicate that the 8203 ion is unidentate and is bonded to the metal through sulphur. 

Waiter-Levy, D. Groult, and J. W. Visser, Bull. Soc. chim. France, 1974, 383. 

Marecek, J. Bares, and E. Erdos, Coll. Czech. Chem. Comm., 1975, 40, 827. 

The stoicheiometry and kinetics of reaction of aqueous ammonia solutions of copper(ii) ions with thiosulphate ion in the presence of oxygen have been examined. The amount of oxygen consumed and the relative amounts of the final sulphur products, namely trithionate and sulphate ions, are dependent on the initial 8203 concentration and pH. The most active species for SjOe formation is a tetra-amminecopper(ii) complex having one axial 8303 and one axial O2 ligand. A complex having both axial and equatorial 8203 ligands as well as an axial O2 was suggested as the reactive intermediate for sulphate formation. 

A specific rate constant for the rapid complexation of Ag ion by thiosulphate ion in aqueous solution has been determined, using the recently developed laser optical-acoustic technique for measurement of sound absorption. In aqueous solution the predominant complexed species is the 1 2 ion [Ag(8203)2] . 

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