THE CRYSTAL AND MOLECULAR STRUCTURE TRANS-AZIDOBIS (DIMETHYLGLYOXIMATO) PYRIDINECOBALT(III)

Abstract

Abstract Crystals of trans-azido bis(dimethylglyoximato)pyridinecobalt(III) are monoclinic, space group P21/c. The unit cell constants are a = 8.731(3), b = 13.982(3), c = 17.961(5) Å,β = 126.80(1), V = 1755.7 Å3, and Z = 4. The structure was determined from three dimensional X-ray data (2152 independent reflections) obtained by the θ-2θ scan method using a CAD–4 automated four-circle diffractometer. Structure solution was effected by Patterson and Fourier methods and refined by block diagonal least squares method to a conventional R value of 0.041. The two dimethyl glyoximato monoanions occupy the equatorial plane with pyridine and azide groups in the axial positions. Azide N–N bond distances were found to be 1.155(6) and 1.126(7) Å with the longer bond adjacent to the cobalt atom. Cobalt–nitrogen bonds in the axial positions are significantly longer than those in the equatorial plane. Although the O–O interatomic distances between the separate oxime anions are close to 2.5 Å the hydrogen bonding is decidedly unsymmetrical.