Decomposition of zinc (1-hydroxyethylidene)diphosphonate induced by aliphatic amines and ammonia. Molecular structures of ammonium (1-hydroxyethylidene)diphosphonates.

A suspension of sparingly soluble zinc (1-hydroxyethylidene)diphosphonate ZnH2L•2H2O (H4L = MeC(OH)[P(O)(OH)2]2) is rapidly transformed into an aqueous solution when treated with ammonia or aliphatic amines (hexamethylenediamine, triethylamine, tert-butylamine, di-n-butylamine) containing no hydrophilic groups −OH and −(OCH2CH2)n−. The dissolution effect is due to the decomposition of the coordination polymer giving ammonium derivatives. Dehydrated dry powders of the corresponding ammonium compounds based on triethylamine, tert-butylamine, or di-n-butylamine rapidly dissolve in water to form transparent colorless solutions, whereas hexamethylenediamine and ammonia derivatives are poorly soluble. (1-Hydroxyethylidene)diphosphonic acid forms ammonium salts with hexamethylenediamine, triethylamine, and tert-butylamine. The molecular structures of these compounds are considered. [ABSTRACT FROM AUTHOR]