Investigation of the IR spectra of weakly hydrogen-bonded complex Cl3CH…O(CD3)2 in a cryosolution in liquid krypton

Resumo

The IR absorption spectra of cryosolutions of chloroform, dimethyl ether, and their mixtures in liquefied krypton have been measured. It has been shown that, in solutions of mixtures, Cl₃CH…O(CD₃)₂ complexes with a weak hydrogen bond are formed. The spectral characteristics of individual absorption bands that refer to proton donors and to proton acceptors have been determined. From temperature measurements of the integrated intensities of the bands of monomers and of the complex (T ~ 120–160 K), the enthalpy of the complex formation has been estimated. The measurement data have been analyzed in comparison with the results of ab initio calculations in terms of the МР2/6-311++G(2df, 2pd) approximation. The analysis has been done taking into account peculiarities of the dipole moment function of chloroform and possible effects of the anharmonic interaction between the С–Н stretching vibration and the overtone of the Cl–C–H bending vibration.