in water byproducts: ammonia; under N2, mixt. of NH4(Fe4S3(NO)7) and 10percent NaOH soln. stirred and heated in water bath at 80°C for ca. 4 h; filtered hot, concd., left standing at room temp. overnight, crystals collected, washed with Et2O, dried in vac., purified by dissolution in THF under N2, filtration, evapn. in vac., drying in vac.;