HCl in water addn. of mixt. of ligand and 2 equiv. HCl to 1 equiv. K2PtCl6 soln., addn. of further 1 equiv. ligand, stirring at 50°C for 2 h; crystn. (room temp., 1 week), collection (filtration), washing (EtOH, Et2O), drying (vac.); elem. anal.;

in water treatment of ligand with 2 equiv. HCl, addn. to 1 equiv. K2PtCl6 at 55°C (pptn.), standing for 24 h, addn. of further 1 equiv. ligand, stirring at 55°C for 4 h; fractional crystn. on slow evapn., collection (filtration), washing (EtOH, Et2O), drying (vac.); elem. anal.;