Structure of sulfanilamide-containing cobalt(III) dioximates with the [ZrF6]2− and [BF4]− anions

Abstract

The complexes [Co(DH)2(Sam)2]2[ZrF6]·5H2O (I) and [Co(DH)2(Sam)2][BF4]·H2O (II), where DH− is the dimethylglyoxime monoanion, and Sam is para-aminobenzenesulfamide (sulfanilamide, white streptocid), were synthesized, and their crystal structures were determined by X-ray diffraction analysis. The coordination polyhedron of the Co3+ atom is an N6 octahedron formed by four nitrogen atoms of the two dimethylglyoxime residues and two nitrogen atoms of the Sam fragments. The latter are realized in virtually parallel orientation relative to the polyhedron of the metal atom and its equatorial plane; the average value of the dihedral angles is 26.8(1)°, and there is π-π interaction between the benzene rings of the Sam fragments and the π delocalized equatorial metallocycle. The deviation of the cobalt atom from the four-angle plane is up to 0.009(1) A. The (Co-N)DH− and (Co-N)Sam distances in the [Co(DH)2(Sam)2]+ complex cations vary from 1.892(2) A to 1.907(3) A and from 2.000(2) A to 2.012(2) A, respectively. The [ZrF6]2− and [BF4]− complex anions play the major role in crystal formation; they produce a substantial effect on the formation of a complex system of hydrogen bonds.