Isotope Effects in Arene C-H Bond Activation by Cp*Rh(PMe3)
This literature discussion is based on a paper by Bill Jones and Frank Feher (J. Am. Chem. Soc., 1986, 108, 4814-4819). In this paper, they study the activation of aromatic C-H bonds by a rhodium complex. Through careful experimental design, they were able to examine isotope effects on the selectivity of the reaction. Analysis of the rate data allowed them to prepare a reaction coordinate free energy diagram. This paper also introduces the effects of C-H bond breaking in early or late transition states on the vibrational energy spacing at both ground and excited states.