Morpholine action on cobalt complexes of 1-hydroxyethylidene diphosphonic acid

The suspension of poorly soluble cobalt(II) 1-hydroxyethylidene diphosphonate CoH2L reacts with morpholine (M) in aqueous medium to give a soluble compound CoH2L•2М•2Н2О. Reaction with an excess of morpholine leads to formation of anhydrous diphosphonate CoH2L•2М and amine СоМn complexes. The microimpurity of the morpholine acetaminamide O(CH2CH2)2NC(O)CH3 in morpholine under conditions of prolonged aerobic reaction with CoH2L is oxidized into morpholine carbamic acid O(CH2CH2)2NC(O)OH, which joins the morpholine molecule giving an ionic compound [O(CH2CH2)2NC(O)O]- [H2N(CH2CH2)2O]+. 1-Hydroxyethylidene diphosphonic acid with morpholine forms a complex of the H4L•3М composition.