Kinetic study of the homogeneous methanolysis of tetraphosphorus decasulphide
The rate of the homogeneous methanolysis of pure P4S10, dissolved in CS2, has been measured at 0, 15, 25, and 35 °C for various MeOH:P4S10 molar ratios. The sole product detected was (MeO)2PS2H. At not too low concentrations, the reaction is virtually first order in [P4S10] and second order in [MeOH], owing probably to an autocatalytic process. The multistep reaction is kinetically controlled by the initial attack on P4S10; this is tentatively explained by the rigidity and geometry of the P4S10 cage molecule and/or by the spontaneous formation of reactive dithioxophosphoranes ZP(S)2[Z = MeO– or > P(S)S–] from all alcoholysis intermediates. Calculated activation parameters are discussed. Novel data on the solubility of P4S10 are reported.