Novel cobalt(II) coordination complexes based on 3,4,5-trifluorobenzeneseleninic acid and different N-donor ligands

Abstract

Three novel cobalt(II) coordination complexes constructed by 3,4,5-trifluorobenzeneseleninic acid (L) and different N-donor ligands, namely, [Co(4,4′-bpy)(L)2]n (1), [Co(2,2′-bpy)(L)2]n (2), [Co2(en)4(L)2(NO3)4]·(CH3CN)2 (3). (4,4′-bpy = 4,4′-bipyridine, 2,2′-bpy = 2,2′-bipyridine, and en = ethylenediamine) have been designed, synthesized and characterized by IR spectroscopy, elemental analysis, single-crystal X-ray diffraction analyses. In the three complexes above, the 3,4,5-trifluorobenzeneseleninic acid ligand adopt anti–anti bridging coordination mode and all the cobalt ions show distorted octahedral configurations. Complex 1 displays a 2D layer structure, which is further connected by π⋯π interactions to give rise to a 3D supramolecular structure. The structure of complex 2 exhibits 1D tube-like double chain structure and the neighboring chains are further linked by hydrogen-bonds C–H⋯F and π⋯π interactions to form a 3D supramolecular structure. However, complex 3 is a monomer which can be connected into a 2D supramolecular layer through the intermolecular C–H⋯O hydrogen-bonds interaction. In addition, the magnetic properties of complexes 1 and 2 are characterized.