93858-90-3 octaammonium octahydrogen [2,5,8,11,14,17-hexakis(phosphonatomethyl)-2,5,8,11,14,17-hexaazaoctadecane-1,18-diyl]bisphosphonate 93858-91-4 nonaammonium heptahydrogen [2,5,8,11,14,17-hexakis(phosphonatomethyl)-2,5,8,11,14,17-hexaazaoctadecane-1,18-diyl]bisphosphonate