Phosphonite and Phosphinite Complexes

Halogen analogues can also be prepared as, for example, Co(NO)(PF3)2 (MeOPF2) (8.218). Methods of preparation of these complexes include addition (6.234), direct ligand replacement (8.216), sodium borohydride reduction (8.217) or direct modification of the ligand (8.218). 

---

The chemistry of phosphite, phosphonite and phosphinite complexes of palladium(II) generally resembles that of their phosphine analogues. Its description here will therefore be brief, attention being paid to those areas where differences in behaviour are apparent. 

Table 41 Preparations Phosphite, Phosphonite and Phosphinite Complexes...

Four similar papers reporting new cationic and neutral complexes of Pt group metals with phosphite, phosphonite and phosphinite ligands have appeared (see... 

Calculated AG( — 50°Q values are in the range 38-6 to 43-7 kJ mol and rate constants in the range 11 x 10 to 4-9 x 10 s . Similar studies on other Ni(ii) complexes are reported (54,242,243,252). Co(ii) complexes with ethyl phosphite, phosphonite, and phosphinite ligands (L) may be high spin complexes of the type C0CI2L2 or low spin, 5-coordinate complexes of the type C0CI2L3. In organic solvents the equilibrium ... 

The ligand properties of the related phosphonites P(OR)2R and phosphinites P(OR)R2 have attracted little attention.199,200 Reaction with silver chloride generally produced 1 1 complexes of the type AgCIL, whilst with silver nitrate, complex cations of the type AgL4 were generated. The products were characterized by elemental analysis, 7H and 31P NMR spectroscopy and conductivity measurements. 

The menthyl phosphonites and menthyl phosphinites were used for the preparation of F-chiral monodentate ligands. For example, Imamoto used menthyl phosphinite borane complexes for the synthesis of DIPAMP analogues, as shown in Scheme 6 [23]. The treatment of phosphinite borane (/ p)-8 with methyllithium. 

In addition to metallophosphines (8.52), there are also many phosphite (8.53a), phosphonite (8.53b), phosphinite (8.53c) and other complexes which have been studied. Phosphite, phosphonito and phosphinito complexes, which contain M-O-P as well as M-P linkages have also been prepared (Table 8.16). 

Table 42 Structures Phosphite, Phosphinite and Phosphonite Complexes...

Phosphinite- and phosphonite-bearing complexes (Figure 3.1) displayed better catalytic activities, with complete conversions after 5-8 h under aqueous conditions [13]. 

---