Phosphonite complexes

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

The P-Pt coupling data for the platinum- phosphonite complexes published in the literature have been reviewed by Vlugt et and the 7ppt couplings for two new complexes containing novel, sterically constrained diphosphonite ligands with 2-tert-butyl-phenolate and 2,2 -dioxo-3,3 -di-tert-butyl-5,5 -dimethoxy-1,1 -biphenyl groups have been measured by them. 

Low valent transition metal centers preferentially coordinate to the phosphorus in diazaphospholes. Accordingly, P-coordinated complexes of [l,2,3]diazapho-spholes with Cr, W, Fe, and Mn carbonyls were obtained as early as 1980 [1, 2,4], Later, Kraaijkamp et al. observed [108] both P- or -coordination modes in complexes of [l,2,3]diazaphospholes with MX2(PEt3) (M = Pt, Pd X = C1, Br). Methanolysis of these complexes led to the diazaphosphole ring opening and formation of five membered metallacyclic P,/V-chelates (103), incorporating P-bonded phosphonite and /V-coordinated hydrazone functionalities (Scheme 32) [109],... 

The coordination chemistry of the hydrido/phosphine rhenium complexes can be extended to phosphonite and phosphite complexes. This has been demonstrated for monodentate ligands such as P(OEt)3, P(OCH2)3CEt and PPhtORE (R = Me, Et, Pri),2S8779,809,iii8 chelating phos-... 

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 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. 

The planar phosphite complexes [PdX2 P(OR)3 2] have been prepared by a variety of methods, such as the reaction of P(OR)3 with [PdX p in ethanol in the presence of LiX.88 The palladium(II) iodide and P(0-o-tolyl)3 complexes have trans structures or are cisftrans mixtures, but the others are predominantly cis isomers. The phosphonites, P(OR)2Ph, and... 

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