Infrared spectra of halothane-trimethylamine complex in liquefied krypton

The IR absorption spectra of solutions of mixtures of halothane (C$_{2}$HBrClF$_{3}$) and trimethylamine ((CD$_{3})_{3}$N) in liquefied krypton were obtained and analyzed. Bands assigned to weak hydrogen-bonded complexes have been identified. The enthalpy of formation was estimated in a series of temperature experiments on the change in the integral intensities of the bands of monomers and complexes An extremely strong increase in the intensity of the second-order bands attributed to the first overtone of the bending CH vibrations of halothane was found. The effect is determined by strong anharmonic interactions of a resonant nature (Fermi resonance and Darling–Dennison resonance). The results of ab initio calculations reproduce the effects observed in the experiment.