Synthesis, crystal structures and photocatalytic properties of two coordination polymers bearing a flexible 1,5-bis(benzimidazolyl) pentane ligand

Two ternary mixed ligand Co(II) coordination polymers (CPs), {[Co(L1)(tbta)] center dot H2O}(n) (1) and [Co(L1)(niP)](n) (2) [L1 = 1,5-bis(benzimidazolyl)pentane. H(2)tbta tetrabromoterephthalic acid, H(2)nip - 5-nitroisophthalic acid], have been synthesized under hydrothermal conditions and structurally characterized by single -crystal X-ray diffraction, powder X-ray diffraction (PXRD), IR spectroscopy and elemental analysis. 1 consists of infinite two-dimensional (4,4) sheets, which further extend into a three-dimensional supramolecular framework by hydrogen -bonding interactions. 2 exhibits a unique 3D framework with a 2 -nodal (3,5)-connected 3,5T1 topology. Both compounds show high photocatalytic activity for the degradation of methylene blue (MB) dye under UV irradiation. Furthermore, the luminescence properties, thermal behavior and electrochemical behaviors of I and 2 have also been investigated in detail. (C) 2018 Elsevier Ltd. All rights reserved.