Vanadium polyoxoanion-bridged macrocyclic metal complexes: from one-dimensional to three-dimensional structures.

The reactions of four-coordinated transition metal macrocyclic complexes [ML](ClO4)2(L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, M = Ni, Cu) with NH4VO3under different conditions gave four coordination polymers of {[(CuL)0.5(H2L)1.5][H2V10O28]·6H2O}n(1·6H2O), {[NiL]3[V16O38(H2O)]·6H2O}n(2·6H2O), {[NiL][VO3]2·0.33H2O}n(3·0.33H2O), and {[CuL][VO3]2·0.33H2O}n(4·0.33H2O). Single crystal X-ray diffraction analyses reveal that four diverse vanadium polyoxoanions, [H2V10O28]4−cluster, [V16O38(H2O)]6−cage, [V6O18]6−ring, and [VO3]nn−chain, were obtained from the same reactant NH4VO3under different conditions. In 1, the cluster anion [H2V10O28]4−alternately bridges [CuL]2+/[H2L]2+to form a one-dimensional chain, and the [V16O38(H2O)]6−cage in 2links three [NiL]2+into a two-dimensional sheet. Compounds 3and 4show three-dimensional structures, which are constructed by the connections of hexanuclear [V6O18]6−rings with [NiL]2+in 3, and [VO3]nn−chains with [CuL]2+in 4, respectively, generating one-dimensional channels occupied by guest water molecules. [ABSTRACT FROM AUTHOR]