NMR conformational studies of (1,2-bis(diarylphosphino)ethane)(diorgano sulfide)ruthenium complexes

Article abstract of DOI:10.1016/0022-328X(94)80164-9

Some (η⁵-cyclopentadienyl)(1,2-bis(diarylphosphino)ethane)(diorgano sulfide)ruthenium complexes, 5-C5H5)(Ar2PCH2CH2PAr2)(R¹R²S)>BF4 (Ar = Ph, p-Tol; R¹, R² = Ph, Et) were prepared.Variable temperature NMR spectra of these complexes showed the existence of two fluxional processes; inversion at the sulfur atom and δ-λ interconversion of the chelate ring.The former process was slower,and its barriers in these complexes were calculated as ca. 7 kcal mol^-1.The spectral features of ethyl phenyl sulfide complexes suggested that substantiation of the new chiral center at sulfur induces a significant conformational rigidity at the chelate ring. Key words: Ruthenium; Sulfide; Nuclear magnetic resonance; Conformation; Diphosphine