13C NMR Studies of the Chelate Ring Opening-Closing Process in (Nitrilotriacetato)vanadate(￥′) dioxovandate(￥′) Ion

摘要

Activation parameters of the exchange between two types of glycinate groups in (nitrilotriacetato)dioxovanadate(ゴ) ion, [VO2(NTA)]2-, have been determined as the results of 13C NMR measurements over a range of temperatures between 277 and 306。K. The exchange mechanism is proposed on the basis of the chelate ring opening-closing process, assuming rupture of the metal-oxygen (glycinate) bond trans to V = O bond to give a five-coordinated intermediate.