X-Ray diffraction analysis of the disordered crystal and molecular structure of [{Co3(CO)9C}2SCO] : its identity with the previously reported ‘[{Co3(CO)9(CS)}2]’

Abstract

The title compound, obtained from the reaction of [Co₂(CO)₈] with CS₂, has been fully characterized by X-ray diffraction analysis. The incorrectness of the previously reported formulation, [{Co₃(CO)₉(CS)}₂], is ascribed to the disordered –S–C(O)– chain joining the two CCo₃(CO)₉ entities. The compound is triclinic, space group P, with a= 8.794(4), b= 12.576(4), c= 8.113(4)Å, α= 105.14(3), β= 113.32(4), γ= 95.61(1)°, and Z= 1. The cobalt atoms were located by the conventional Patterson method and the C, O, and S atoms by subsequent Fourier-difference maps. The final R value was 0.046 for 2 021 reflections with I > 3σ(I). The central part of the molecule, C–S–C(O)–C, is planar, with large π-electron delocalization and with different orientations with respect to the two Co₃ triangles. Its vibrational modes correspond to the i.r. bands at 1 642 [ν(C–O)], 1 137 [ν(C–C)], and 924 and 768 cm^–1[ν(S–C)].