Isomerization of thiourea to ammonium thiocyanate and isotopic exchange between [35S]thiourea and diphenyl tetrasulphide
Abstract
The specific rate of isomerization of thiourea to ammonium thiocyanate has been determined at 120° in 1 : 1 ethanol–xylene and in ethanol–benzene by radiochromatography using 35S-labelled thiourea. The isotopic exchange between [35S]thiourea and diphenyl tetrasulphide in 1 : 1 ethanol–xylene, studied by radiochromatography, shows that the tetrasulphide exchanges only one sulphur atom with thiourea at 100° and two sulphur atoms at 120°. The rate constant for exchange [k2 9·57·10–7 l (g-atom)–1 s–1] could only be determined at 100° because at 120° the rate of isomerization of thiourea was too high.