Preparation of Phosphite Complexes

Phosphite complexes can be prepared by direct addition (8.196) and (8.197) or by displacement reactions (8.198) through (8.201). 

Reaction (8.197) is of interest since both Co and Co complexes are derived from a Co salt. Hydrido derivatives are made by sodium borohydride reduction of a phosphite and a metal salt (8.201). 

Some mixed phosphite-phosphine complexes can be made by substitution (8.204). The ruthenium complex in (8.205) undergoes rearrangement at the ruthenium atom on heating. 

Copper complexes such as Cu P(OMe)3 4 where Z = NO, Cl, CIO4 are almost white or colourless, as are those of types M(CO)5P(OPh)3, M(CO)4 2P(OPh)3 or M(CO)3 3P(OPh)3, where M = Cr, Mo or W. These carbonyl complexes are based on an octahedral configuration of ligands about the metal atom and exist in isomeric forms which can be isolated (8.206) (L = P(OPh)3). 

The structure of [CuP OPh 3]4 CI4 is based on a cubical arrangement of Cu and Cl atoms similar to that adopted by [AgPEt3l4 CI4. 

---