in water dissolving of (Pt(CH3NH2)4)(PtCl4) under heating in aq. methylamine-soln. and repeated evaporation with concd. HBr-soln.;; washing with HBr-containing H2O and with alcohol; recrystallization in boiling H2O and drying at 100°C;;
in water byproducts: {Pt(CH3NH2)4}Br2; addn. of aq. 33percent methylamine-soln. on an aq. soln. of K2(PtBr4) at 0°C; pptn. of cis-(Pt(CH3NH2)2Br2) in 1 h; addn. of concd. HBr-soln. to the mother-lye forms trans-(Pt(CH3NH2)2Br2);;
