Hydrothermal synthesis, crystal structure and electrochemical behavior of two new isomorphic layered vanadates: [M(dpa)V3O8.5] (M = Cu(II) 1 and Zn(II) 2; dpa = 2,2′-dipyridylamine)

Two new isomorphic vanadates, [M(dpa)V3O8.5] (M = Cu2+ 1, Zn2+ 2; dpa = 2,2′-dipyridylamine) have been synthesized hydrothermally. X-ray crystal analysis reveals that vanadates 1 and 2 exhibit a layered structure constructed from {V3O8.5}2− layers inlaid with [M(dpa)]2+ subunits. The {V3O8.5}2− layers consist of ribbon-like chains of edge sharing {VO5} square pyramids bridged through {V2O7} fragments. Electrochemical measurement shows that lithium ions are reversibly intercalated and deintercalated in vanadate 1.