PLATINUM(II) COMPLEXES OF THE CHELATING TRIPHOSPHINE BIS(3-(DIPHENYLPHOSPHINO)PROPYL)PHENYLPHOSPHINE - P-31 NMR-STUDIES OF THE CIS AND TRANS INFLUENCE ON THESE MODEL COMPOUNDS

A series of planar [Pt(ttp)X]+ (ttp = PhP(CH2CH2CH2PPh2)2; X = CI”, NCS. NO2, H-, CH3-, CH2CN-, COOCH3-, CH2CH=CH2-, and Ph”) and [Pt(ttp)Y]2+ (Y = P(OMe)3 and PEt3) complexes have been prepared and characterized by their elemental analyses, conductivity measurements, infrared spectra, and 'H and 31P NMR spectra. The <r-bonded carbon ligands (X = methyl, cyanomethyl, and allyl) were prepared by oxidative-addition reactions on the Pt(0) compounds Pt(ttp)PPh3 and Pt(ttp)CO. The S02 complex [Pt(ttp)Cl]Cl-S02 is unusual for a S02 -metal complex, as the S02 molecule is sulfur bonded to the ionic chloride to give the S02Cl~ anion, instead of being bonded either to the metal or to one of its ligands. The magnitude of the one-bond platinum-phosphorus coupling constant obtained from phosphorus-31 NMR spectra produces the trans influence series Ph” ~ cr-allyl” >COOCH3- >CH3 >H” >CH2CN” >PEt3 >P(OMe)3 >N02” >-NCS” >Cr. As the fourth ligand (X” or Y) is varied, the changes in the cis coupling constants, ]jp1-pph2, are smaller than the changes in the trans coupling constants, '/P(-fPh- The tr-donor ligands that exert a large trans influence (e.g., CH3” and CH2CH—CH2) display a small cis influence, whereas those ligands that exert a small trans influence (e.g., Cr) produce a relatively large cis influence. The following cis influence series is deduced from the './/>(-/>ph2 values: P(OMe)3 >NCS” >CI“ >PEt3 >N02“ >CH2CN“ >COOHf >H“ >CH3“ >Ph“ >a-aHyl̝. The 31P NMR spectra of several [Pt(ttp)X]+ complexes (X = anionic ligand) demonstrate that the 195Pt satellite patterns are not necessarily the same as the central resonance. © 1979, American Chemical Society. All rights reserved.