Helical Coordination Polymers Based on A Tripodal N-donor Ligand

The coordination polymers [Cu-2(tpim)(2)]center dot 2H(2)O (1) and [Co(H(2)tpim)(2)(MoO4)(2)] (2) [Htpim = 2,4,5-tri(4-pyridyl)-imidazole] were synthesized. Their structures were determined by single-crystal X-ray diffraction and further characterized by elemental analyses, IR spectroscopy, and TG analyses. Compounds 1 and 2 both contain chiral helical-layer structures. Compound 1 exhibits a novel 3D (3,3,4)-connected framework with (4 center dot 6 center dot 8)(6 center dot 8(2))(4 center dot 6 center dot 8(3)center dot 10) topology, which is constructed from left- and right-helices. Compound 2 displays a 2D chiral helical-layer structure which can be rationalized as a (3,6)-connected 2D kgd (kagome dual) net, and these 2D layers are further extended by hydrogen-bonding interactions to form a 3D supramolecular network. By comparing compounds 1 and 2, it is believed that the tripodal N-containing ligand (Htpim) plays a key role in the construction of helical coordination polymers. In addition, the photoluminescence property of compound 1 and the magnetic property of compound 2 were studied.