Halogen-Metall-Austausch an Dihalogenphosphan-Komplexen; Synthese von Diphosphan-, Diphosphen- und Phosphiniden-Derivaten / Halogen Metal Exchange; Diphosphane-, D iphosphene-, Phosphinidene-Complexes

Abstract

Complexes of dihalophosphanes LnM-P(R)(Hal)2 (LnM = 16-electron fragment e.g. Cp(CO)2Mn) undergo transformations into phosphinidene-, diphosphene- or diphosphanederivatives upon treatment with metallating agents (e.g. tBuLi/TMEDA). On the basis of many experimental observations a unified reaction scheme is proposed for these syntheses. The preparation and reactivity of diphosphane complexes LnM-(R)P(H) -(R)P(H)-MLn is discussed in some detail. Analytic, spectroscopic and X-ray techniques are used to establish the results. A prominent finding is the observation of an extremely long P-P distance (235.1(3) pm) for the sterically strained meso-[Cp(CO)2Mn]2(tC4H9)P(CH3) -(tC4H9)P(CH3)