31P and 195Pt solid-state NMR and DFT studies on platinum(i) and platinum(II) complexes

31P and 195Pt solid state NMR spectra of anti-[(PHCy)ClPt(?-PCy2)2Pt(PHCy)Cl] (3) and [(PHCy2)Pt(?-PCy2)(?2P,O-?-POCy2)Pt(PHCy2)] (Pt-Pt) (4) were recorded under cross polarization/magic-angle spinning conditions (31P) or with the cross polarization/Carr-Purcell-Meiboom-Gill pulse sequence (195Pt) and compared to the data obtained by relativistic DFT calculations of 31P and 195Pt CS tensors and isotropic shielding at the ZORA spin-orbit level. A good agreement with the experimental results was found and it was possible to rationalize the chemical shift differences of 195Pt and 31P nuclei between compounds 3 and 4 as mostly due to a change (in opposite directions for 195Pt and 31P) of the principal component of the shielding tensor perpendicular to the molecular plane defined by the Pt and P atoms. Paramagnetic and spin-orbit terms were found to be the most important contributions to 195Pt and 31P shielding.