in water ZnI2 dissolved in demineralized H2O; H2NCN in demineralized H2O added with stirring; stirred for 3 h; filtered; ppt. washed with H2O and EtOH; dried in high vac. at 120°C for 12 h;
in water (Ar); ppt. washed several times (water); dried in vacuo; heating pellet in silver crucible sealed in glass tube to 843 K over a period 70 h; held for 150 h; slow cooled to room temp.; crystn.;
