Assembly of niobium-phosphate cluster and in situ transition-metal-containing derivatives

Abstract

A novel phosphorus incorporated peroxopolyoxoniobate (CN3H6)6H4[P4Nb6(O2)6O24]·4H2O (1) has been successfully synthesized and characterized. Compound 1 possesses a cluster of [P4Nb6(O2)6O24]10− and can be viewed as the fusion of two {P2Nb3(O2)3O14} subunits by corner-sharing of bridging oxygen atoms. Furthermore, by reacting transition metals with the polyanion [P4Nb6(O2)6O24]10− formed in situ, we have discovered a series of transition-metal-containing niobium phosphate cluster derivatives, (CN3H6)4H4[{Cd(H2O)4}{P4Nb6(O2)6O24}]·7H2O (2), Cs3H3{[M(H2O)4.5]2[P4Nb6(O2)6O24]}·5H2O [M = Co (3), Ni (4), Zn (5)] and Cs3H3[{Cd(H2O)4}2{P4Nb6(O2)6O24}]·12H2O (6). Compounds 2–6 are based on the {P4Nb6(O2)6O24}10− cluster and 3, 4 and 5 show zero-dimensional constructions whereas 2 and 6 can form 1D chains attributed to the larger radius of Cd2+.