New microporous copper(II) coordination polymers based upon bifunctional 1,2,4-triazole/tetrazolate bridges

A series of Cu(II) coordination polymers, [Cu(mu(2)-L1)(3)]PO3F (1), [Cu-2(mu(2)-L1)(4)(mu(4)-L1)](NO3)(4)center dot 2H(2)O (2), [Cu(mu(2)-L1)(2)(mu(2)-X)]X center dot 12H(2)O (X = Cl, 3; Br, 4), [Cu-4(mu(2)-OH)(2)(mu(4)-L1)(3)(mu(2)-L1)(2)(H2O)(2)](CF3SO3)(6)center dot 10H(2)O (5), [Cu-3(mu(2)-OH)(2)(mu(4)-L1)(H2O)(2)(mu(3)-SO4)(2)] (6), [Cu(mu(4)-L1)(mu(2)-SO4)]center dot 6H(2)O (7), [Cu-2(mu(4)-L2)(3)]Cl center dot 12H(2)O (8) involving new bifunctional p-phenylene bridged bi(1,2,4-triazole) and mixed 1,2,4-triazole-tetrazolate based ligands (L1 = 1,4-phenylene-4,4'-bi(1,2,4-triazole), HL2 = 5-(4-[1,2,4] triazol-4-yl-phenyl)-1H-tetrazole) has been prepared under hydrothermal conditions and their structures have been established by means of X-ray diffraction. In crystal structures 1-8, the organic ligands, utilizing two neighboring nitrogen atoms (N1, N2 in triazole (trz) and N2, N3 in tetrazolate), behave either in mu(2) or in mu(2) + mu(4) manner binding the adjacent metal centers or Cu-3(mu(2)-OH)(2) clusters into 1D columns (1, 3, 4), 2D zigzag layers (2) and 3D frameworks (5-8). The mutual coplanarity between uncoordinated trz moiety and p-phenylene spacer as well as its radial disposition around the "propeller-like'' [Cu-2(eta(2)-trz)(3)] subunits is a crucial factor, which specifically mediates multiple pi-pi interactions through intercalation of the neighboring Cu(eta(2)-trz)(n) (n = 2,3) axles, and as a consequence, affording one-dimensional channels with trigonal (1, 2) or rhombic geometry (3, 4). Large rectangular channels have been realized in neutral [Cu(mu(4)-L1)(mu(2)-SO4)](n) (7) and cationic [Cu-2(mu(4)-L2)(3)](n)(n+) (8) frameworks, in which the remaining void space is filled by water molecules and counter anions (Cl-).