Phosphito, Phosphonito and Phosphinito Complexes

Most recently studied are the phosphito (RO 2PO-, phosphonito R(RO)PO- and phosphinito R2PO-complexes. These compounds can involve both M-P and M-O-P linkages. 

Of special interest is the double sandwich Co cyclopentadienyl derivative (8.219e), which can be made from a phosphonite ester by reaction (8.220). The Co analogue, (tr-CjHj) C03 P(0)(0R)2 J X is also known. Some halogen derivatives can be made by direct modification of ligands (8.221). 

Phosphite complexes such as (8.219c) are best regarded as dialkyl phosphite salts (6.358). The complexes RuCl2(NO)[ (EtO)2PO 2H]2 and Pd2(SCN)2 (Ph2PO)2H 2 contain very short hydrogen bonds (Chapter 13.1). 

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