Three cobalt(II) coordination polymers constructed from flexible bis(thiabendazole) and dicarboxylate linkers: crystal structures,fluorescence, and photocatalytic properties

Three Co(II) coordination polymers, namely, {Co(btbb)_0.5(ndc)(H₂O)}_n (1), {[Co(btbb)(bpdc)]·1.5H₂O}_n (2), and {[Co(btbp)₂(3-npa)]·2H₂O}_n (3) (btbb = 1,4-bis(thiabendazole)butane, btbp = 1,3-bis(thiabendazole)propane, H₂ndc = 2,6-naphthalenedicarboxylic acid, H₂bpdc = 4,4′-biphenyldicarboxylic acid and 3-H₂npa = 3-nitro phthalic acid) were synthesized under hydrothermal conditions. Their X-ray crystal structures show that complexes 1 and 2 both have 2D uninodal 3-connected hcb (honeycomb) structures. Complex 1 is further extended into a threefold interpenetrating 3D 4,4-connected mog (moganite) supramolecular architecture with the point symbol of {4.6⁴.8}₂{4².6².8²} by O–H···O hydrogen bonding interactions. Complex 2 shows a 3D supramolecular framework involving π···π stacking interactions. Complex 3 features a uninuclear structure, which is further assembled into an ordered 2D hydrogen-bonded-driven pattern with O–H···O and O–H···N hydrogen bonding interactions. The fluorescence spectra and photocatalytic properties of complexes 1–3 for degradation of methyl orange were investigated.