Stabilization of the first selenogermylene as the monomeric pentacarbonyltungsten(0) complex

Article abstract of DOI:10.1021/om00119a007

Bis[(2,4,6-tri-tert-butylphenyl)seleno]germylene, formed in situ by reaction of lithium 2,4,6-tri-tert-butylphenyl selenide with the germanium dichloride dioxane complex, was trapped as the monomeric pentacarbonyl[bis((2,4,6-tri-tert-butylphenyl)seleno)germylene]tungsten(0) complex. Reaction of bis-(2,4,6-tri-tert-butylphenyl) diselenide with the germanium dichloride dioxane complex provides dichlorobis((2,4,6-tri-tert-butylphenyl)seleno)germane. This tetravalent germanium compound and bis-(2,4,6-tri-tert-butylphenyl) diselenide were identified as byproducts when preparation and isolation of the monomeric selenogermylene was attempted. The structure of the selenogermylene tungsten(0) complex was determined from single-crystal X-ray diffraction data. The complex crystallizes (with one toluene per molecule) in the monoclinic space group P2₁/c with a = 1077.4 (2), b = 1667.2 (2), c = 2880.9 (2) pm, β = 98.33°, and Z = 4. The molecule contains trigonal planar germanium with bonds to tungsten and to two nonequivalent selenium atoms (Ge-Se, 231.4 (2) and 234.6 (2) pm; Ge-W, 252.8 (1) pm). Well-resolved ¹H, ¹³C, and ⁷⁷Se NMR signals for the two (2,4,6-tri-tert-butylphenyl)seleno groups of the selenogermylene complex indicate hindered rotation around the Ge-Se bonds at room temperature in solution.