in water; dimethyl sulfoxide; N,N-dimethyl-formamide a soln. of the ligand added dropwise to a stirred soln. of K2(PtCl4) (room temp., excluding light), DMSO added, color changed to yellow; solvent removed (vac.), treated with water, pptn., filtered off, washed(water), dried (vac., 80°C); elem. anal.;