Crystal Chemical Role of o-Halobenzene Carboxylate Ions in the Structure of 3d Metal Coordination Compounds

A crystal-chemical analysis of o-halobenzene carboxylate-containing complexes of 3d metals has been performed using the stereoatomic model of crystal structure and the characteristics of the Voronoi–Dirichlet polyhedra. The coordination types of o-halobenzene carboxylate anions with respect to 3d metals are considered. The effect of the coordination type on the characteristics of M–O bonds (M = 3d metal) in the crystal structures was revealed. The electron donor capacity of o-halobenzene carboxylate anions with respect to 3d metals was quantified based on the 18-electron rule. It is shown that the o-halobenzene carboxylate anions are not planar, and the carboxyl groups are rotated relative to the plane of the benzene ring through an angle φ, and it was established that there is a linear relationship between the φ angle and the value of the solid angle of the face of the Voronoi–Dirichlet polyhedron corresponding to the Hal/CCOO contact.