Platinum complexes tertiary phosphites

Tertiary phosphite complexes of platinum(O) can be prepared by the hydrazine reduction of PtCl2 P(OR)3 2 (equation 384), or by replacement of triphenylphosphine in Pt(PPh3)3 (equation 385).1233 Alternatively the complexes can be prepared from Pt(j73-C3H5)(r/5-Cp) and the phosphite.1268 Heteronuclear INDOR measurements show that 2/(PP) has a value of +81 Hz in Pt P(OMe)3 4. A detailed synthesis of Pt P(OEt)3 4 has been published from K2PtCl4 and triethyl phosphite with KOH (equation 386).1267 The product is obtained as colorless crystals which can be handled in air. 

Phosphorus-31 2D-EXSY NMR spectra have afforded evidence of sym-cis/sym-trans interconversions in a series of cyclopalladated tertiary phosphite complexes of type [Pd(/i-Cl)(P(OR )2(OC6H3R ))]2. The platinum analog behaved in a similar manner/ P NMR 2D-EXSY spectroscopy was also employed to probe the dynamics of interconversion between covalent and dative metal-bonded isomers of the mixed metal dinuclear complex [NiPd(CNMe)3(dppm)2](PF6)2. Isomer populations were strongly solvent-dependent with free energies of activation for interconversion of ca 67 kJ mol at 298 Dinuclear complexes of trimethylplatinum(IV) halides have been synthesized (26). The dominant solution structures were... 

The first examples of five-coordinate platinum(II) complexes of the type [Pt(PR3)L]2+ (L = tris(2-(diphenylphosphino)ethyl)phosphine R = Et, OMe, OEt) (104) containing only P-donor atoms have been prepared by the reaction of [PtClL]+ with an appropriate monodentate tertiary phosphine or phosphite ligand.284 Triaryl phosphines and phosphites do not react with the precursor complex, even at elevated temperatures, most probably due to the considerable steric interactions that would occur upon the approach of the P-donor ligand to the platinum(II) center. 

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