Metallophosphines and Metallophosphites

The simplest examples of compounds with X-P-M bridges are provided by the metallophosphines (8.27a) and (8.28a), where M is usually a group I or group II metal. Some of these compounds, however, exist as metal cations and (organo) phosphide anions (8.27b) and (8.28b), the adopted configuration being influenced both by M and the nature of R. 

Phosphide anions are excellent nucleophiles and are very reactive. 

Metallophosphites in covalent form (8.29) provide other examples of 3-coordinated P compounds, although they are devoid of M-P linkages and are not strictly metallophosphorus compounds (Chapter 6.8). 

The simple alkali metal phosphines (phosphides) can be obtained by straightforward methods (8.30) through (8.34). A P-C linkage is broken in (8.33). 

These compounds are extremely sensitive to water and other protoic solvents (8.35) moreover, many inflame in air. Most are soluble in ether, tetrahydrofuran and dioxane, but insoluble in benzene. The trifluoromethyl derivative in (8.34) is soluble in liquid NH3 and stable at low temperature. 

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