Acyclic Polythioether Complexes: Preparation and Crystal Structure of Tricarbonyl(2,5,8-trithianonane)molybdenum(0)

Tricarbonyl(2,5,8-trithianonane)molybdenum(0) has been prepared and characterized by single-crystal X-ray crystallography. The compound crystallizes in the monoclinic space group P2₁/n with a = 7.255 (3) Å, b = 12.270 (3) Å, c = 15.229 (3) Å, β = 96.51 (2)°, V = 1346.9 (6) ų, and Z = 4. The structure was solved by using the heavy-atom Patterson method followed by least-squares refinement using 3039 independent reflections to a final R₁ value of 0.026 (R₂ = 0.031). A detailed comparison is made between the structural and spectroscopic data obtained for tricarbonyl(2,5,8-trithianonane)molybdenum(0) and those previously reported for tricarbonyl(1,4,7-trithiacyclononane)molybdenum(0). This comparison suggests that the sulfur donor orbitals for tricarbonyl(2,5,8-trithianonane)molybdenum(0) are more favorably directed toward the empty metal orbitals than those for tricarbonyl(1,4,7-trithiacyclononane)molybdenum(0).