Assembly,Fluorescent and Adsorption Properties of Two Cadmium(II)/Cobalt(II) Coordination Complexes Functionalized by the Flexible Bis(Pyridyl)-bis(Amide) Ligand

A new cadmium(II) and a new cobalt(II) coordination complexes Cd₅(BTB)₄(HL)₂]·2H₂O (1) and Co(HBTB)(L)]·2H₂O (2) H₃BTB?=?1,3,5-tri(4-carboxylphenyl)benzene, L?=?N,N′-bis(3-pyridyl)octandiamide] were prepared under the solvothermal conditions by the assembly of cadmium(II)/cobalt(II) chloride, the flexible bis(pyridyl)-bis(amide) ligand L and the aromatic tricarboxylic acid H₃BTB. The structures of complexes 1–2 have been characterized by X-ray single crystal diffraction analyses, infrared spectroscopy (IR), powder X-ray diffraction (PXRD) and thermogravimetric (TG) analyses. Complex 1 is a 3D metal–organic network with the penta-nodal (2,4,4,5,6)-connected {4·6³·8·10}₂{4²·6⁵·8³}₂{4³·6³}₂{4⁶·8⁹}{6}₂ topology constructed from the 3D Cd₅(BTB)₄]_n^2n? coordiantion framework and the protonated HL ligands. Complex 2 displays a binodal (4,4)-connected {6⁴·8·10}{6} topological 2D layered architecture based on the 1D Co(HBTB)]_n chains and the 1D CoL]_n chains, which are further linked by hydrogen bonding interactions to form a 3D supramolecular network. Moreover, the fluorescent properties of the cadmium(II) complex and the dyes adsorption performances of complexes 1–2 have been studied.