Syntheses, characterization of three new cobalt(II) complexes with 2-phenylsuccinic acid and flexible bis(imidazole) linkers

Abstract

Bis(imidazole) derivatives (obix, mbix, pbix = 1,2-/1,3-/1,4-bis((imidazol-1-yl)methyl)benzene) with Co(II) and flexible 2-phenyl succinic acid (phsucH2) afforded three coordination polymers namely, [Co(µ-phsuc)(µ-obix)]n (1), {[Co(µ-phsuc)(µ-mbix)]⋅H2O}n (2), {[Co(µ4-phsuc)(µ-pbix)0.5]⋅H2O}n (3) and they were characterized by elemental analysis, magnetic susceptibility, solid-state UV–Vis. and IR spectroscopies and single crystal X-ray diffraction techniques. The phase purities of the complexes were confirmed by powder X-ray diffraction analysis. X-ray diffraction studies have shown that compounds 1 and 2 crystallize in the monoclinic system, in the P21/c space group, while compound 3 crystallizes in the P-1 space group in the triclinic system. In all compounds, bis(imidazole) ligands act as bis(monodentate), whereas 2-phenylsuccinate ligands act as both monodentate and bidentate bridges in 1, bis(monodentate) bridges in 2, tetrakis(monodentate) bridges in 3. The complexes displayed 2D layer structures and adjacent 2D layers are joined by C–H···π interactions in 1, weak C–H···O interactions in 2, π···π stacking and weak C–H···π interactions in 3 to form a 3D supramolecular network. The contribution of the binding positions of the imidazole groups to the phenyl ring in bis(imidazole) ligands to the structure and structural diversity are also discussed. In addition, the thermal properties of the compounds were investigated in the study.