Syntheses, structures and adsorption properties of two-dimensional Cd(II) coordination polymers

Solvothermal reactions of Cd(CH3COO)(2) and 2,2'-(1,3-phenylene)-bis(N-pyridin-3-yl)acetamide (1,3pbpa) with 1,3-phenylenediacetic acid (1,3-H(2)PDA), 4,4'-oxybis(benzoic acid) (4,4'-H(2)OBA) and 1,4-benzenedicarboxylic acid (1,4-H2BDC) afforded [Cd(1,3-pbpa)(1,3-PDA)(n), 1, [Cd(1,3-pbpa)(OBA)center dot 2H(2)O](n), 2, and [Cd(1,3-pbpa)(1,4-BDC)(H2O)center dot EtOH center dot H2O](n), 3, respectively, which were structurally characterized as two-dimensional (2D) coordination polymers. Complexes 1 and 2 show the rare {8(4).12(2)}{8)(2)-2,4L2 topology, whereas complex 3 adopts a new topology with a point symbol of {12}{4.12(5)}{4}, which can be further simplified as the 4(4)-sql topology and the 6(3)-hcb topology, respectively. Desolvated product of 2 shows a moderate uptake of CO2 and a good selectivity over N-2, which also exhibits a better H-2 and CO2 sorption compared to the activated product of 1, indicating the effect of ligand type on the adsorption properties of 2D complexes with the 4(4)-sql topology. Thermal gravimetric analysis (TGA) and the solid state luminescence properties of 1-3 have also been investigated. (C) 2019 Elsevier Ltd. All rights reserved.