Synthesis, Characterization, Solvatochromic Behavior, Crystal Structures of Complexes [CoIII(salophen)(thioacetamide)2]ClO4, [CoIII(salophen)(thiobenzamide)2]ClO4

Two new cobalt(III) complexes of the Schiff base N,N''-disalicylidene-1,2-phenylendiimine dianion (salophen), trans-[CoIII(salophen)(ta)2]ClO4, (ta = thioacetamide) (1) and trans-[CoIII(salophen)(tb)2]ClO4, (tb = thiobenzamide) (2) were synthesized and characterized using single-crystal X-ray diffraction and spectroscopic techniques. Both complexes show solvatochromism in a variety of solvents. Complex (1) crystallized from CHCl3 as a solvate of orthorhombic symmetry, space group Pca21 with a = 17.3480(10) Å, b = 18.7522(10) Å, c = 18.8128(11) Å, a = β = γ = 90°, and Z = 8. The cobalt(III) center lies in a distorted octahedral environment. The crystal structure of (1) consists of two independent [CoIII(salophen)(ta)2]+ cations and ClO4- anions held together essentially via hydrogen bonds and π-π stacking interactions. Complex (2), forming also a CHCl3 solvate, crystallized in the monoclinic space group P21/n with a = 14.710(3) Å, b = 13.506(3) Å, c = 18.595(4) Å, β = 100.295(4)Å, and Z = 4. The geometry around cobalt(III) center is a distorted octahedron. The crystal structure of (2) contains a [CoIII(salophen)(tb)2]+ complex with a remarkably twisted salophen ligand. Both complexes, (1) and (2), contain approximately one disordered CHCl3 molecule per Co in the solid state.