Two novel transition metal–organic frameworks based on 1,3,5-benzenetricarboxylate ligand: Syntheses, structures and thermal properties

Two novel transition metal–organic frameworks, [Zn6(OH)3(BTC)3(H2O)3]⋅7H2O (1) and [Cd(BTC)(H2O)]⋅[HIM] (2) (H3BTC = 1,3,5-benzenetricarboxylic acid), have been synthesized under hydrothermal conditions and characterized by single crystal and variable temperature powder X-ray diffraction (VTPXRD), IR spectroscopy, elemental analyses, ICP measurements, and coupled TG–MS analyses. Compound 1 crystallizes in the trigonal space group R3c, and could be described as a 3D porous network consisting of (Zn2O8)n zigzag chains and bridging BTC ligands with 1D channels along c axis. Compound 2 crystallizes in the monoclinic space group P21/c, and exhibits a 2D framework made up of CdO6 octahedra and BTC ligands parallel the bc plane. TG–MS and VTPXRD studies reveal that 1 is stable up to 320 °C under air, and 2 stable up to 220 °C.

► [Zn6(OH)3(BTC)3(H2O)3]⋅7H2O (1) and [Cd(BTC)(H2O)]⋅[HIM] (2) were synthesized.
► H3BTC = 1,3,5-benzenetricarboxylic acid.
► 1 is of a 3D network consisting of (Zn2O8)n zigzag chains and BTC ligands with 1D channels.
► 2 exhibits a 2D framework made up of CdO6 octahedra and BTC ligands.
► 1 was stable up to 320 °C under air, and 2 stable up to 220 °C.