Poly(Tertiary Phosphines and Arsines). XI. Phosphorus-31 Nuclear Magnetic Resonance Studies on Some Metal Complexes of Poly(Tertiary, Phosphines).

摘要

Proton noise-decoupled pulsed Fourier transform phosphorus-31 NMR spectra of metal complexes of the di(tertiary phosphine) (CH3)2PCH2CH2P(C6H5)2, the symmetrical tri(tertiary Phosphines) R'P(CH2CH2PR2) (R and R' = methyl or phenyl), the unsymmetrical tri(tertiary phosphine) (CH3)2PCH2CH2P(C6H5)CH2CH2P(C6H5)2, and the tripod tetra(tertiary Phospines) P(CH2CH2PR2)3 (R = methyl or phenyl) are reported and discussed on the basis on known structures of the metal complexes. Uncomplexed and complexed phosphorus atoms in complexes such as biligate monometallic (triphos)W(CO)4, monoligate monometallic C5H5Fe(CO)(triphos)(COCH3), biligate monometallic (tetraphos)Cr(CO)4, and triligate monometallic (tetraphos)Cr(CO)3 can easily be differentiated by this method. The anomalously large downfield shift of phosphorus atoms in five-membered chelate rings is increased if the phosphorus atom belongs to two or three fused five-membered chelate rings. Thus the center phosphorus atom in the tetraligate monometallic tripod tetra(tertiary phosphine) complexes ((tetraphos)NiCl) (PF6), which belongs to three fused five-membered chelate rings, exhibits downfield coordination chemical shifts in excess of 150 ppm.