An N.M.R. Study of Electron Donor-Electron Acceptor Interaction Between Aromatic Hydrocarbons and Diazines

Abstract

Equilibrium constants have been measured by n.m.r , spectroscopy for the electron donor- electron acceptor interaction between a number of aromatic hydrocarbons and diazines . The values obtained have shown that the interaction is weak, and that the aromatic hydrocarbon acts as the electron donor and the diazine as the electron acceptor in the systems studied. Chemical-shift data have provided evidence for the relative positioning of the donor and acceptor components within the various complexes. The effect of temperature on the equilibrium constant for complex formation between (¹H₆)benzene and pyrazine has shown that the enthalpy of formation is close to zero.