26978-38-1Relevant articles and documents
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)
Berg, David J.,Andersen, Richard A.,Zalkin, Allan
, p. 1858 - 1863 (2008/10/08)
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)°.
