68958-87-2 EINECS 273-376-9 Hydrogen pentapotassium (((ethylenebis(nitrilobis(methylene)))tetrakis(phosphonato))(8-))nickelate(6-) Nickelate(6-), (((1,2-ethanediylbis((nitrilo-kappaN)bis(methylene)))tetrakis(phosphonato-kappaO))(8-))-, pentapotassium hydrogen, (OC-6-21)- Pentapotassium nickelous 1,2-ethane di(nitrilodi(methylene phosphonate))