Electron-transfer chemistry of (Me5C5)2Yb: Cleavage of diorganoperoxide and related chalcogenides to give (Me5C5)2Yb(ER)(L) (E = O, S, Se, or Te; L = a Lewis base). Crystal structure of (Me5C5)2Yb(TePh)(NH3)

Article abstract of DOI:10.1021/om00098a025

The divalent metallocenes of ytterbium (Me₅C₅)₂Yb(OEt₂) or (Me₅C₅)₂Yb(NH₃)₂ react with molecules of the type REER to give the trivalent ytterbium complexes (Me₅C₅)₂Yb(ER)(L), where L is OEt₂ or NH₃, E is S, Se, or Te, and R is a phenyl or substituted phenyl group. The ammonia complexes are easier to characterize than the diethyl ether complexes since the latter complexes lose ether in the solid state and give unsatisfactory microanalytical data whereas the ammonia complexes give satisfactory elemental analyses. In addition, the line width of the Me₅C₅ protons in the ¹H NMR spectra of the diethyl ether complexes is ca. 500 Hz whereas the line width at half-height is ca. 50 Hz for the ammonia complexes, consistent with the notion that the barrier to chemical exchange is higher for the ammonia complexes. The peroxides ROOR, where R is Me₃C or Me₃Si, give the alkoxides (Me₅C₅)₂Yb(OR)(NH₃), and Et₂NC(S)SS(S)CNEt₂ gives the known (Me₅C₅)₂Yb(S₂CNEt₂). In contrast, dialkyl dithiophosphinates give (Me₅C₅)₂Yb(S₂PR₂) and R₂PPR₂, where R is Me or Et. The synthetic routes developed in this work are the best methods currently available for synthesis of these trivalent species. The crystal structure of (Me₅C₅)₂Yb(TePh)(NH₃) has been done. The crystals are orthorhombic, P2₁2₁2₁, with a = 11.823 (3) ?, b = 25.917 (6) ?, c = 8.539 (2) ?, and V = 2616.5 ?³. For Z = 4, the calculated density is 1.69 g cm^-3. The structure was refined by full-matrix least squares to a conventional R factor of 0.046 [4991 data, F² > σ(F²)]. The Yb-Te distance is 3.039 (1) ?, and the Yb-Te-C(Ph) angle is 113.0 (3)°.