| 19505095 |
Piro NA, Cummins CC: An unusual P-P double bond formed via phospha-Wittig transformation of a terminal PO complex. J Am Chem Soc. 2009 Jul 1;131(25):8764-5.
The terminal phosphorus monoxide complex (OP) Mo (N [(t) Bu] Ar)(3), 1 (Ar = 3,5-Me (2) C (6) H (3)), undergoes an O-for-PSiR (3) metathesis reaction with the niobium phosphinidene complex (i) Pr (3) SiPNb (N [CH (2)(t) Bu] Ar)(3), 2, to generate the oxoniobium complex ONb (N [CH (2)(t) Bu] Ar)(3), 3, and the diphosphenido complex (i) Pr (3) SiPPMo (N [(t) Bu] Ar)(3), 4. The structure of 4, as determined by X-ray crystallography, contains a "singly bent" diphosphenido moiety, suggesting that the diphosphenido ligand serves as a 3e (-) donor to a formally d (2) metal center. This bonding characterization was supported by DFT calculations and is unique among known diphosphenido complexes. Diphosphenido 4 was found to react over time to produce products consistent with a bimolecular degradation pathway where the terminal phosphide complex PMo (N [(t) Bu] Ar)(3), 5, serves as a stable leaving group. Mixtures of 4 and PPh (3) were observed to set up an equilibrium (K (eq) = 0.7) between 4, PPh (3), and the products of phosphinidene transfer, 5 and (i) Pr (3) SiP=PPh (3). |
81(1,1,1,1) |