COORDINATION AGGREGATES OF BIFUNCTIONAL BETA-DIPHOSPHORYL COMPOUNDS AS STUDIED BY P-31 AND CD-113 NMR IN SOLUTION

Bifunctional beta-diphosphorylated ligands of general formula [R(2)P(O )]N-2-X-N[P(O)R(2)](2) with R = OCH3 or N(CH3)(2) form stable complexe s with a variety of metal cations. Under certain conditions, coordinat ion aggregates can be obtained as shown by multinuclear NMR spectrosco py, UV/vis spectrometry, and electrochemical techniques. We have studi ed systems formed by the above-mentioned compounds with the divalent m etal cations Mg2+ and Cd2+ by P-31 and Cd-113 NMR spectroscopy. The sp ectra reveal the presence of different types of coordinating groups fo r the ligands and different environments for the metal ions in solutio n. A detailed analysis of the data in combination with conductivity an d viscosity measurements allowed us to conclude that polyionic chainli ke structures are formed in these systems.