IR spectral density of H-bonds. Both intrinsic anharmonicity of the fast mode and the H-bond bridge. Part II: Isotopic effect

Anomalous isotopic effects on the position and the shape of the υs(X-H→…Y) stretching vibration bond of hydrogen-bonded systems have been studied theoretically by applying a previous model [N. Rekik, N. Issaoui, H. Ghalla, B. Oujia, M.J. Wojcik, J. Mol. Struct. (Theochem) 821 (2007) 9-29]. The study of this effect is undertaken for weak to medium-strong H-bonded systems. Numerical results show that the relation between the isotopic frequency ratio, 〈ω〉H/〈ω〉D and ω°H/〈ω〉H, derived in this paper is confirmed by published experimental data.