Self-assembly of two chiral zinc coordination polymers based on N-benzoyl-l-glutamic acid: Influence of different N-donor ancillary ligands on structural arrangement and photoluminescent properties

The room-temperature reactions between N-benzoyl-l-glutamic acid (H2bzgluO), zinc salts and ex-bidentate N-donor ligands in acidic CH3OH/H2O solutions yielded two new coordination polymers, [Zn(bzgluO)(bpp)]n·1.75nH2O (bpp = 1,3-bis(4-pyridyl)propane) (1) and [Zn(bzgluO)(4,4-bipy)0.5]n (4,4-bipy = 4,4-bipyridine) (2). The two complexes have been characterized using single-crystal X-ray diffraction, infrared spectra, elemental analysis, thermogravimetric analysis and powder X-ray diffraction analysis. The X-ray structural determination indicates that complex 1 crystallizes in the monoclinic space group C2 and displays a 2-D wave-like sheet structure, while complex 2 crystallizes in the tetragonal space group P4(3)2(1)2 and presents a 3-D network structure. The structural difference indicates that the effect of N-donor ancillary ligand is critical in construction of polymeric arrangement. Moreover, the solid-state photoluminescent properties of the two coordination polymers change also according to the N-donor ancillary ligand introduced.