Cobalt(II)-terephthalate frameworks containing bis(benzimidazole) derivative Co-ligands: Syntheses, crystal structures, catalytic and fluorescence properties

摘要

Two metal-organic coordination polymers of Co~(II) with the molecular formulae [Co(L_1)(tp)(H_2O)_2]_ n (1) and [Co(L_2)(tp)·H_2O]_n (2) [L_1 = 1, 4-bis(benzimidazole-1-ylmethyl)- benzene; L_2 = 1, 1-(1, 4-butanediyl)bis(5, 6-dimethylbenzimidazole); tp = terephthalate] were synthesized and characterized by single-crystal X-ray diffraction studies, infrared spectroscopy (IR), thermogravimetric analysis (TGA), X-ray powder diffraction (XRPD), and elemental analysis. The structure determination of complex 1 reveals a 2D layer with (4, 4) topology, with Co~(II) ions at the nodes connected through tp and L_1 co-ligands. Complex 2 is the first example of a four-connected SrAl_2 structure type (sra, 4 ~26~38 topology) with threefold interpenetration in Co~ (II) coordination frameworks, forming by bridging L_2 and tp co-ligands. In addition, the fluorescence and catalytic performances of the complexes for the degradation of methyl orange were investigated.