The doubly-bonded ditungsten anion [W2Cp2(μ-PPh2)(NO)2](-): an entry to the chemistry of unsaturated nitrosyl complexes.

Abstract

Complex [W2Cp2(μ-I)(μ-PPh2)(NO)2] was prepared by reacting [W2Cp2(μ-I)(μ-PPh2)(CO)2] with NO at 233 K followed by decarbonylation in refluxing toluene. It was reduced by Na(Hg) in acetonitrile to give Na[W2Cp2(μ-PPh2)(NO)2], the first anionic nitrosyl complex featuring a metal-metal double bond (computed W-W = 2.580 Å). Reactions of the latter anion with (NH4)PF6 and [AuCl{P(p-tol)3}] gave the hydride [W2Cp2(μ-H)(μ-PPh2)(NO)2] and the cluster [AuW2Cp2(μ-PPh2)(NO)2{P(p-tol)3}] respectively, also featuring multiple W-W bonding (experimental W-W ca. 2.75 Å), and its reaction with S8 yielded the electron-precise derivative Na[W2Cp2(μ-PPh2)(μ-S)(NO)2], which was methylated by Me2SO4 to give the thiolate complex [W2Cp2(μ-PPh2)(μ-SMe)(NO)2].