Synthesis and characterization of two cobalt(II) coordination polymers based on 5-tert-butyl isophthalic acid and bis(benzimidazole) ligands

Abstract

Two cobalt(II) coordination polymers, namely [Co(bbdmbm)(tbi)·H2O]n (1) and [Co(bmb)1.5(tbi)]n (2), (bbdmbm = 1,1′-(1,4-butanediyl)bis(5,6-dimethylbenzimidazole), bmb = 1,4-bis(2-methylbenzimidazol-1-ylmethyl) benzene, H2tbi = 5-tert-butyl isophthalic acid), have been synthesized and characterized by physico-chemical and spectroscopic methods and also by single-crystal X-ray diffraction. Complex 1 features a 1D ladder-like chain and is further extended into a 3D supramolecular architecture via strong O–H···O hydrogen bonds. Complex 2 exhibits a 2D corrugated (4,4) network constructed with bmb and tbi ligands, which is further assembled into a 3D 3,4,4-connected supramolecular framework with 3,4,4T25 topology through weak C–H···O hydrogen-bonding interactions. The fluorescence properties and catalytic activities of both complexes for the degradation of Congo red in a Fenton-like process have been investigated.