SYNTHESIS AND CHARACTERIZATION OF 1,2,3-TRIPHOSPHOLIDE ANIONS

The R'-1,3-diphenyl-2,3-dihydro-1H-1,2,3-triphospholes are synthesized as P2-P2' dimers 4 by insertion of phosphorus into the P-P bond 1,2-d ihydro-1,2-diphosphetes. When R = R' = Ph, the cleavage of the P-Ph an d P2-P2' bonds of 4 by potassium in dimethoxyethane yields the 4,5-dip henyl-1,2,3-triphospholide ion 5, which has been completely characteri zed by negative ion mass spectrometry and H-1, C-13, P-31 NMR spectros copy. This ion is stable toward water in a basic medium. It reacts wit h [M(CO)5] (M = Mo, W) to give first the 1,3-bis-complex and then the 1,2,3-tris-complex. The same synthesis can be transposed for R = Ph, R ' = (t)Bu to give the corresponding ion 6 but fails for R = R' = Et.