N-15 AND P-31 NMR-STUDIES OF CYANO-(TRIALKYL TRIARYL)PHOSPHINE-GOLD(I) COMPLEXES/

The ligand scrambling reaction of R(3)PAuC(15)N to form (R(3)PAu+ and Au((CN)-N-15)(2)(-) has been studied (by N-15 and P-31 NMR spectroscop y) for R = Me, Et, i-Pr, and Ph. P-31 NMR Showed two resonances due to R(3)PAuCN and (R(3)PAu+ species, while N-15 NMR showed only an averag ed resonance due to R(3)PAuC(15)N and Au((CN)-N-15)(2)(-) species, exc ept for Et(3)PAuC(15)N, for which two separate resonances were detecte d. R(3)PAu(13)C(15)N (where R = Me, Et and Ph) complexes were also pre pared and (2)J(P-31-C-13) as well as (3)J((31)p-N-15) constants were m easured. The free activation energy for ligand scrambling in Ph(3)PAuC N was determined by P-31 NMR band shape analysis to be 39.7 kJ/mol(-1) .