in ethanol stoich., to a soln. of metal salt added a soln. of ligand, heated with stirring; ppt. filtered, washed (ice-cold ethanol), dried (silica gel); elem. anal.;

in ethanol addn. of Ni(NO3)2 to 2 equiv. of ligand, heating for 10 min; cooling in ice (crystn.), collection, washing (ice-cold alcohol), drying(vac., over silica gel); elem. anal.;