Effets de la liaison hydrogene sur les vibrations ν(CH) et ν(OH) dans les complexes X-H…O(H)CH(CD3)2

Abstract

When the complex X-H…O(H)CH(CD₃)₂ in a carbon tetrachloride solution is formed between a proton donor XH and isopropanol(D₆), we observe for the ν(CH) wavenumber of isopropanol(D₆) an increase of about 15 to 45 cm⁻¹ which depends on the proton donor ability of XH ; we also observe a decrease for the ν(OH) wavenumber of about 13 to 21 cm⁻¹. The ν(OH) anharmonicity is unchanged. When the CH group is at a greater distance from the hydroxyl group [in the (CF₃)₃COH…O(H)CD₂CD₂H complex] the increase for $\text{ν}$(CH) is only 3 cm⁻¹. The ν(OH) wavenumber for the free hydroxyl group in the homomolecular linear dimer of isopropanol(D₆) is 5 cm⁻¹ lower than the observed value for the monomer. The intensity of the ν(CH) band generally decreases in the complexation, that of the ν(OH) band is slightly modified, or increases when the proton donor is perfluorotertiobutanol.