Two solvent directed zinc(II) coordination polymers with 1-D single-zigzag chain and 1-D double-zigzag chains

Abstract

Two coordination polymers, {[Zn(NiL)(DMA)(H2O)2] (DMA)(H2O)} n (1) (DMA = N,N-dimethylacetamide) and {[Zn2(NiL)2(DMF)(H2O)4] · 3DMF} n (2) (DMF = N,N-dimethylformamide), have been prepared by reactions of Zn(NO3)2 · 6H2O and NiL in CH2Cl2-DMA–H2O and CH2Cl2-DMF–H2O, respectively. H2L denotes dimethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo-9,10-benzo-[1,4,8,11]tetraazacyclotetradecine-13,18-dicarboxylate. Single-crystal X-ray diffraction analyses reveal that coordination geometries around Ni(II) are identical with slightly distorted square planar and all Ni–N bonds are very short. Complex 1 shows 1-D zigzag chain structure, while 2 has 1-D double-zigzag chains. The chains, which are packed parallel in 1 and 2, are interconnected by lattice solvent through O–H···O and C–H···O hydrogen bonds to form 3-D supramolecular networks. We discuss solvent effects on assembly of the two coordination polymers. The results reveal that coordinated solvent has influence on the assembly procedure.