in water heating Pt-complex and Ba-compd. in water at 60°C for 10 h; filtn., evapn. to dryness, dissolution of residue in DMF, hot filtn., concn., pptn. with ethanol, elem. anal.;

sodium hydroxide in water addn. of malonic acid to a soln. of Pt-complex in water, adjusting pH to 5.5 by addn. of aq. NaOH, heating at 40°C for 4 h; cooling yields compd., elem. anal.;

in water byproducts: BaSO4; dropwise addn. of a soln. of Pt-complex in water to a suspn. of barium malonate in water, heating at 60°C for 4 h; hot filtn., concn., elem. anal.;