Pseudo-Polymerization via Symmetric O -H -O Bonding of the Cobaloximatic Acid, Hydro-trans-Diiodobis(2,3-butanedione dioximato(1-)-N ,N′)cobaltate(III). X-Ray Crystal and Molecular Structure

Abstract

The structure of hydro-trans-diiodobis(2,3-butanedione dioximato)cobaltate(III), H(CoI2(dmg)2) (dmg- = dimethylglyoximate) has been determined by single crystal X -ray diffraction at ambient temperature. The crystals are monoclinic, space group C 2/c, C8H15CoI2N4O4, Mr = 543.98; a = 15.714(6), b = 7.408(3), c = 13.944(5) Å; β = 107.76(3)°; V = 1545.85 Å3; Z = 4; Dc = 2.34 Mg m -3. The com pound is best visualized as a monobasic acid. The molecules are linked together into two-dimensional network, where linkage parallel to the ac plane is effected by weak intermolecular iodine interactions (I ···I = 3.826 Å), and linkage along the b axis by symmetric intermolecular O - H - O bridges (O - Ointermol = 2.499 Å) involving the acidic protons. Each molecule contains two equivalent intramolecular O - H - O bridges (O ··· Ointrarnol = 2.603 Å). The coordination geometry around Co is a distorted (4+2) octahedron of four chelating equatorial N atoms and two apical iodine atoms. The rectilinear I- Co- I triads are arranged in infinite, faintly zigzagged heteroatomic chains propagating parallel to the ac plane.