Construction of noninterpenetrating and interpenetrating Co(ii) networks with halogenated carboxylate modulated by auxiliary N-donor co-ligands: structural diversity, electrochemical and photocatalytic propertiesElectronic supplementary information (ESI) available. CCDC 1514725-1514730 for CPs 1-6. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6dt04516b

Six Co( ii )-based coordination polymers (CPs) with characteristic frameworks and topologies-namely, [Co(L1)(DCTP)] n ( 1 ), [Co(L2)(DCTP)] n ( 2 ), [Co(L3)(DCTP)] n ( 3 ), {[Co 3 (L4) 3 (DCTP) 3 ·H 2 O]·H 2 O} n ( 4 ), [Co(L5) 1.5 (DCTP)] n ( 5 ) and [Co(L6)(DCTP)] n ( 6 )-were successfully hydrothermally synthesized by employing the halogenated linear ligand 2,5-dichloroterephthalic acid (H 2 DCTP). The interpenetrated structures could be rationally modulated by auxiliary N-donor co-ligands containing 1,1′-(1,4-butanediyl)bis-1 H -benzimidazole (L1), 1,4-bis(5,6-dimethylbenzimidazol-1-yl)-2-butylene (L2), 1,2-bis(2-methylbenzimidazol-1-ylmethyl)benzene (L3), 1,4-bis(2-methylbenzimidazol-1-ylmethyl)benzene (L4), 1,2-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene (L5) and 1,4-bis(5,6-dimethylbenzimidazol-1-ylmethyl)benzene (L6). These diaphanous crystals were clearly characterized by elemental analysis, infrared (IR) spectra and X-ray powder diffraction (XRPD) as well as single-crystal X-ray diffraction analysis. With the aid of the flexible N-donor co-ligands, CP 1 occupies a non-interpenetrated 2D sheet with the point symbol {4 4 ·6 2 } sql net topology, CP 2 possesses a 3D hexagon-shaped network with the point symbol {6 6 } three-fold interpenetrated sqc6 topology, CP 3 exhibits a 2D layer with the point symbol {4 4 ·6 2 } sql net topology, CP 4 reveals an unusual 3D framework with the point symbol {4 2 ·6 3 ·8} three-fold interpenetrated sra topology, CP 5 has a 3D hexagon-shaped network with the point symbol {6 6 } two-fold interpenetrated sqc6 topology, while CP 6 displays a 3D hexagon-shaped network with the point symbol {6 6 } three-fold interpenetrated sqc6 topology. The diverse structures of CPs 1-6 illustrate that the substitute group and position of the methyl group of the bis(benzimidazole) derivatives play a significant role in the assembly of such interpenetrated frameworks. Moreover, luminescence properties and thermal behavior, as well as the electrochemical and photocatalytic properties of CPs 1-6 on the degradation of methylene blue, are also presented. Six Co( ii ) complexes with 2,5-dichloroterephthalate and bis(benzimidazole) were synthesized and characterized, which manifest photocatalytic activities.