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 NH4VO3 under different conditions gave four coordination polymers of {[(CuL)(0.5)(H2L)(1.5)][H2V10O28]center dot 6H(2)O}(n) (1 center dot 6H(2)O), {[NiL](3)[V16O38(H2O)]center dot 6H(2)O}(n) (2 center dot 6H(2)O), {[NiL][VO3](2) center dot 0.33H(2)O}(n) (3.0.33H(2)O), and {[CuL][VO3](2) center dot 0.33H(2)O}(n) (4.0.33H(2)O). Single crystal X-ray diffraction analyses reveal that four diverse vanadium polyoxoanions, [H2V10O28](4-) cluster, [V16O38(H2O)](6-) cage, [V6O18](6-) ring, and [VO3](n)(n-) chain, were obtained from the same reactant NH4VO3 under 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 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](6-) rings with [NiL](2+) in 3, and [VO3](n)(n-) chains with [CuL](2+) in 4, respectively, generating one-dimensional channels occupied by guest water molecules.