Proton Transfer in Hydrogen Bond and Its Participation in π-Electron Systems

Abstract

The infrared spectra of OH or NH groups in hydrogen bonds in 3µ region are divided into two (or three) types according to their wavelengths and intensities. The first group is of the alcoholic type, and the second group is observed when conjugated π-electron systems combine the hydrogen bonds and when the effect of the proton transfer across the hydrogen bond and the “ Antenna Effect ” are important. Qualitative discussions on the proton transfer are developed and numerical calculations are carried out with simple symmetrical double minimum potentials. The linear combination method solving such problems is shown to be numerically incorrect, though it is convenient for a qualitative consideration. Further evidence and biological importance of the hydrogen transfer participating π-electron systems are discussed.