Four Complexes with the Rigid Ligand 1,4-Bis(1H-imidazol-4-yl)benzene and Varied Carboxylate Ligands

Four metal‐organic coordination polymers [Co2(L)3(nipa)2]·6H2O (1), [Cd(L)(nipa)]·3H2O (2), [Co(L) (Hoxba)2] (3) and [Ni2(L)2(oxba)2(H2O)]·1.5L·3H2O (4) were synthesized by reactions of the corresponding metal(II) salts with the rigid ligand 1,4‐bis(1H‐imidazol‐4‐yl)benzene (L) and different derivatives of 5‐nitroisophthalic acid (H2nipa) and 4,4′‐oxybis(benzoic acid) (H2oxba), respectively. The structures of the complexes were characterized by elemental analysis, FT‐IR spectroscopy and single‐crystal X‐ray diffraction. Complexes 1 and 3 have the same one‐dimensional (1D) chain while 2 is a 6‐connected twofold interpenetrating three‐dimensional (3D) network with α‐Po 412·63 topology based on the binuclear CdII subunits. Compound 4 features a puckered two‐dimensional (2D) (4,4) network, and the large voids of the packing 2D nets have accommodated the uncoordinated L guest molecules. An abundant of N–H···O, O–H···O and C–H···O hydrogen bonding interactions exist in complexes 1–4, which contributes to stabilize the crystal structure and extend the low‐dimensional entities into high‐dimensional frameworks. Lastly, the photoluminiscent properties of compounds 2 were also investigated.