New complexes of gadolinium with dicarboxylate diphosphabetaines

The processes of complexation of dicarboxylate diphosphabetaines with gadolinium nitrate were studied, as a result of which stable polymer metal complexes insoluble in inorganic and organic solvents were obtained. To carry out these reactions, dicarboxylate diphosphabetaines were previously synthesized: 3,3'-(propane-1,3-diylbis (diphenyl)phosphoniondiyl)dipropanoate and 3,3'-(hexane-1,3-diylbis (diphenyl)phosphoniondiyl)dipropanoate, based on maleic acid with 1,3-bis(diphenylphosphino)bisphosphinspropane and 1,6-bis(diphenylphosphino)bisphosphinshexane. The structure of dicarboxylate diphosphabetaines and poly-nuclear polymer complexes of gadolinium has been confirmed by modern physical and chemical methods of research, including NMR and IR spectra, elemental and X-ray structural analysis, thermal stability has been studied by simultaneous thermogravimetry and differential scanning calorimetry.