ON THE PROTONATION EQUILIBRIA OF CYCLO-μ-IMIDO-POLYPHOSPHATE ANIONS (II)

Abstract

³¹P NMR chemical shift changes upon protonation and deprotonation of anions of cyclo-triphosphate, cyclo-mono-μ-imido-triphosphate, cyclo-di-μ-imido-triphosphate, and cyclo-tri-μ-imido-triphosphate have been measured in order to obtain microscopic information on the proton bindings. It has been revealed that hydrogen bonding is formed among the phosphate groups belonging to the cyclic trimers, probably due to proximity of the neighboring phosphate units fixed to rigid rings.