Estimating the Effective Steric Impact of PtBu2Me, PiPr3, and PCy3
摘要:
Enthalpies of reaction of Ru(CO)(2)L(2) (L = (PPr3)-Pr-i, P(t)Bu(2)Me, and PCy(3)) with MeNC, PhC=CPh (both addition reactions) and PhCC-H (C-H oxidative addition) in toluene ape exothermic in the range 10-25 kcal/mol and are interpreted in terms of P(t)Bu(2)Me being more bulky than (PPr3)-Pr-i or PCy(3). Enthalpy comparisons show that the larger cone angle of PCy(3) than of (PPr3)-Pr-i can be overcome by the greater donor power of PCy(3); the origin of the greater donor power of PCy(3) is discussed.