Crystal structure of tris(quinoxaline-2,3-dithiolato)molybdate(V); a distorted trigonal prismatic complex

Abstract

The anion [Mo(qdt)₃]^–(qdt = quinoxaline-2,3-dithiolate) has been prepared by iodine dioxidation of the corresponding dianion. The compound [PPh₄][Mo(qdt)₃] crystallizes in triclinic space group P with a= 12.077(5), b= 12.519(5), c= 15.297(6)Å, α= 89.76(3), β= 81.09(3), γ= 80.50(3)°, and Z= 2. The complex has a distorted trigonal prismatic MoS₆ core with a mean Mo–S distance of 2.393(1)Å and a mean twist angle of 14.6°. This monoanion is more significantly distorted from ideal trigonal-prismatic geometry than is the dianion, [Mo(qdt)₃]^2–, contrary to the results expected on the basis of previous molecular orbital calculations for tris(dithiolene) complexes.