Topological structural diversification of zinc coordination polymers caused by the spacers of different dicarboxylates.

As a new generation of multi-functional materials, crystalline coordination polymers have attracted widespread attention due to their fascinating framework structures, interesting topologies and potential applications. Two new coordination polymers, namely, poly[[μ-trans-1,2-bis(pyridin-3-yl)ethylene-κN:N']bis(μ-terephthalato-κO:O':O'')dizinc(II)], [Zn(CHO)(CHN)] or [Zn(tp)(3,3'-dpe)], (I), and poly[diaqua[μ-trans-1,2-bis(pyridin-3-yl)-ethylene-κN:N']bis(μ-furan-2,5-dicarboxylate-κO:O')dizinc(II)], [Zn(CHO)(CHN)(HO)] or [Zn(fdc)(3,3'-dpe)(HO)], (II), have been prepared by the hydrothermal reactions between Zn(NO)·6HO and trans-1,2-bis(pyridin-3-yl)ethylene (3,3'-dpe) with two similar dicarboxylic acids, i.e. terephthalic acid (Htp) and furan-2,5-dicarboxylic acid (Hfdc), respectively. The coordination framework of (I) is a 3D pcu net with the point symbol 46. The void space of the single framework in (I) is filled by the mutual interpenetration of two crystallographically equivalent networks, forming a threefold interpenetrating 3D architecture. Compound (II) is a 2D 3-connected coordination network parallel to the bc plane with the Schläfli symbol 6. Neighbouring 2D coordination networks are further connected to each other via hydrogen-bonding interactions to produce a 3D supramolecular framework. The thermal stability and photoluminescence properties of these two coordination polymers have also been investigated.