Solvent-dependent formation of two Pb(II) coordination polymers based on 4,4?-azodibenzoic acid linker: crystal structures, fluorescence, and thermal properties.

Solvothermal reactions of Pb(OAc)2·2H2O with 4,4?-azodibenzoic acid (H2L) in DMSO (DMSO?=?dimethyl sulfoxide) and DMF/H2O (DMF?=?N,N?-dimethylformamide) at 90?°C gave two Pb(II) coordination polymers (CPs), [PbL(DMSO)]n(1) and [PbL(H2O)]n(2). Complexes1and2were characterized by elemental analysis, IR spectroscopy, powder X-ray diffraction, and single-crystal X-ray diffraction. Compound1possesses a 2-D staircase-like network based on pairs of left and right helical 1-D [Pb(CO2)2(DMSO)]nchains, and is further assembled into a 3-D supramolecular architecture with a 41263topology through intermolecular hydrogen bond interactions between the neighboring networks. Within the 1-D Pb–O–Pb chain, the DMSO terminally coordinates to Pb(II). Complex2has a 3-D motif containing 2-D Pb-carboxylate layers with H2O bridging neighboring Pb ions in a 4664topological structure. The formation of1and2provides insight into the effect of solvents on the construction of CPs under solvothermal conditions. Stabilities and photoluminescent properties of1and2were also investigated. [ABSTRACT FROM AUTHOR]