in ethanol; water soln. of Ni salt in H2O heated to 60-70°C; soln. of ligand in EtOH added over 30 min; stirred at 60-70°C for 2 h; evapd. by 2/3 of initial vol.; cooled to room temp.; stored for 2 d; ppt. collected by filtration; detd. by elem. anal., gravimetric analysis and X-ray diffraction;