Crystal and molecular structure of tetracarbonyl(3,6-dithiaoctane)chromium(0): evidence for π bonding by a thioether ligand

Abstract

The crystal and molecular structure of the title compound has been determined by single-crystal X-ray diffraction techniques, from diffractometer data. Crystals are monoclinic, a= 13.657(6), b= 14.168(5), c= 8.560(2)Å, β= 123.48°, space group P2₁/a. The structure has been refined by full-matrix least-squares methods to R 0.040 for 2 453 independent reflections. Co-ordination about the central chromium atom is distorted octahedral. Mean metal–ligand bond lengths are :Cr–S 2.418(1), Cr–C(cis) 1,887(3), and Cr–C(trans) 1.831(3)Å, consistent with a significant π component in the Cr–S bonds. The different bond orders of the cis- and trans-Cr–C bonds is also reflected in the lengths of the C–O bonds.