Modulating the polyoxometalate-based inorganic-organic hybrids from simple chains to complicated frameworks via changing POM clusters

Investigation into a hydrothermal reaction system with a copper salt, 1-(imidazo-1-ly)-4-(1,2,4-triazol-1-ylmethyl) benzene) (itb) ligand and three types of polyoxometalates (POMs) led to the preparation of three new coordination polymers, [Cu-2(itb)(4)(H4P2W18O62)]center dot H2O (1), [Cu(itb)(4)(HPW12O40)]center dot 4H(2)O (2) and [Cu-2(itb)(2)(Mo8O26)]center dot 6H(2)O (3). The three coordination polymers were characterized by elemental analyses, single-crystal X-ray diffraction, powder X-ray diffraction, XPS and IR spectra. Structural analyses show that with modulating the type of POM anions from [Mo8O26](4-) and [PW12O40](3-) to [P2W18O62](6-), the three coordination polymers possess distinct structural motifs: simple one-dimensional (1D) chain (1), 1D + 1D -> 2D interdigitated architectures (2) and complicated 3D frameworks consisting of both meso-helixes and left/right-helixes (3). The distinct structural features of the three coordination polymers suggest that the POM anions should play a significant role in the process of assembly. The electrocatalytic and luminescent properties for coordination polymers 1-3 have been investigated.