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

The reactions of four-coordinated transition metal macrocyclic complexes ML(2) (L = 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane, M = Ni, Cu) with NH4VO3 under different conditions gave four coordination polymers of {[(CuL)(0.5)(H2L)(1.5)][H2V10O2)] x 6H(2)O}(n) (1x6H(2)O), {NiL[V16O38(H2O)] x 6H(2)O}(n) (2 x 6H(2)O), {[NiL]VO(3) x 0.33H2O}(n) (3.0.33H(2)O), and {[CuL]VO(3) x 0.33H(2)O}(n) (4 x 0.33H2O). Single crystal X-ray diffraction analyses reveal that four diverse vanadium polyoxoanions, [H2V1oO28)(4-) cluster, V16O38(H2O) cage, V6O18 ring, and VO(3)(n-) chain, were obtained from the same reactant NH(4)VO(3) under different conditions. In 1, the cluster anion H2V10O28 alternately bridges [CuL]2+/[H2L]2+ to form a one-dimensional chain, and the V16O38(H2O) cage in 2 links three [NiL]2+ into a two-dimensional sheet. Compounds 3 and 4 show three-dimensional structures, which are constructed by the connections of hexanuclear V6O18 rings with [NiL]2+ in 3 and VO3(n-) chains with [CuL]2+ in 4, respectively, generating one-dimensional channels occupied by guest water molecules.