Crystal and Molecular Structure of Tris(cyclopentadienyltricarbonylrnolybdenum)thallium(III), Tl(Mo(CO)₃(π-C₅H₅))₃

The crystal and molecular structure of a potentially highly conducting complex tris(cyclopentadienyltricarbonylmolybde-num)thallium(III), Tl(Mo(CO)₃Cp)₃ (Cp = π-C₅H₅), has been determined from three-dimensional X-ray data collected by counter techniques. The coordination around the central thallium atom is trigonal pyramidal with an average Tl-Mo bond distance of 2.965 A and an average Mo-Tl-Mo bond angle of 119.7°. individual Tl-Mo bond distances and Mo-Tl-Mo bond angles differ significantly from these average values. The T1 is 0.586 (1) Å out of the plane of the three Mo atoms. No other metal-metal interactions are observed. Crystal data are as follows: triclinic, space group C_i¹ -P1, a = 11.131 (9) Å, b = 17.305 (16) Å, c = 6.833 (9) Å, α = 98.59 (5)°, β= 96.45 (5)°, γ= 79.51 (5)° (temperature 22°), Z = 2;d_obsd = 2.3 (1)g/cm³, d_calcd = 2.44 g/cm³. The structure was refined using 2060 independent reflections for which Fo² > 3σ(Fo²) and the refinement converged to a conventional R factor (on F) of 0.030.