A series of σ-bonded phosphine and arsine gold carbaborane compounds, 1-R′-2-ER3Au-1,2-closo-C2B10H10 (R′ CH2OCH3 or Ph, ER3 PPh3, P(o-tol)3, PCy3, PEt3 or AsPh3) have been prepared by reaction between ER3AuCl and Li[1-R′-1,2-closo-C2B10H10] in Et2O. Consideration of their 11B NMR and (where appropriate) 31P NMR chemical shifts implies that the closo-carbaborane ligands function as efficient electron donating groups. Comparison of the AuC distance in 1-CH2OCH3-2-AsPh3AU-1,2-closo-C2B10H10 (1e) and AsPh3AuCH3 (3) suggests that the gold-carbon bond in the former is stronger, and this is supported by analysis of the results of molecular orbital calculations at the extended Hückel level on model compounds. closo-Carbaboranes bonded to metal atoms via a MC bond are thereby shown to be good σ-donor ligands.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry