Threefold Interpenetrated Cadmium(II) Organic Framework based on 3-(5-(Pyridin-4-yl)-1 H-1,2,4-triazol-3-yl)pyridine and 1,1′-Biphenyl-4,4′-dicarboxylate.

The coordination polymer [Cd(HL)(BPDA)] n · nH2O ( 1) based on 3-(5-(pyridin-4-yl)-1 H-1,2,4-triazol-3-yl)pyridine (HL) and 1,1′-biphenyl-4,4′-dicarboxylic acid (H2BPDA) was hydrothermally synthesized and characterized by single-crystal X-ray diffraction, XRPD, IR spectroscopy, and elemental analysis. The asymmetric unit of compound 1 consists of one crystallographically independent CdII ion, one HL ligand, 'two half' BPDA2- ligand, and one lattice water molecule. There are two crystallographically different BDPA2- moieties, but each of them is placed in a symmetry element. The BPDA2- ligands and CdII ions connected to2D sheet, and the 2D sheets are connected to a 3D MOF by the HL ligands. Each dimeric CdII unit links six nearest neighbors through the BPDA2- and HL ligands, and the dimeric CdII units are centrosymmetric. Two parallel HL ligands connect two dimeric CdII units, generating long Cd2-HL-Cd2-HL rings, also centrosymmetric. So we can define the dimeric CdII unit as a 6-connected node. Thus, the 3D structure can be described as a threefold parallel interpenetrated bsn beta-Sn topology. In addition, the optical properties of compound 1 and the free ligand H L were investigated. [ABSTRACT FROM AUTHOR]