Coordination polymers constructed from an asymmetric biphenyl-dicarboxylate and N-donor ligands: structures and photoluminescent properties

Two new metal coordination polymers, [Zn₂(bpdc)₂(bip)(H₂O)]_n (1) and [Cd(bpdc)(bip)] _n (2) [H₂bpdc = biphenyl-2,4′-dicarboxylic acid and bip = 1,5-bis(2-methyl-imidazol-1-yl)pentane], have been synthesized and characterized by IR, elemental analysis, and X-ray diffraction. In 1 and 2, the carboxylates adopt three coordination modes: bis-monodentate, monodentate, and bis-chelating. Compounds 1 and 2 are two-dimensional layer structures, but have different topological net: (3,6)-connected net with (4³)₂(4⁶.6⁶.8³) and 4-connected net (4⁴.6²), respectively. Luminescent properties of 1 and 2 are investigated.