sodium hydroxide in water; N,N-dimethyl-formamide Pt-compd. dissolved in DMF with heating, addn. of the acid and aq. NaOH, heated in an unstoppered flask at 60°C for 20 h; cooled, filtered, addn. of ether;

1: [PtI2(en)] With silver sulphate in water T=50°C; 24 h; 2: barium malonate in water T=40°C;

in water byproducts: AgI; Pt- and Ag-complex mixed together in water, stirred in dark for 2-3 d; ppt. filtered, filtrate evapd. to dryness;