Electrostatics determine vibrational frequency shifts in hydrogen bonded complexes

Abstract

The red-shifts in the acetylenic C–H stretching vibration of C–H⋯X (X = O, N) hydrogen-bonded complexes increase with an increase in the basicity of the Lewis base. Analysis of various components of stabilization energy suggests that the observed red-shifts are correlated with the electrostatic component of the stabilization energy, while the dispersion modulates the stabilization energy.