Design, structure and properties of a novel 3D metal-organic framework constructed from N-donor ligand supporting Cd(II)-carboxylate layer

A novel three-dimensional microporous metal-organic framework (MOF), Cd3(CTC)2(TED)(H2O)2 · (H3O)2Cl2 (1) (H3CTC = cis,cis-1,3,5-cyclohexanetricarboxylic acid and TED = triethylenediamine), has been synthesized under mild condition with mixed H3CTC and TED ligands. It is of particular interest that twofold alternate (6,3) net subunits constructed from Cd centers and H3CTC ligands are supported by linear TED ligands along the c axis to build a 3D architecture. This structure exhibits about 7.2 × 8.4 Å2 channels along the [100] direction. The water adsorption isotherm shows type I behavior with approximately 0.07 mL/g pore volume. The fluorescent emission spectrum of polymer 1 shows a sharp blue-shift peak at 522 nm (λex = 235 nm).