Quantum-mechanical study of energies, structures and vibrational spectra of the HF complexed with dimethyl ether

Interaction energies, geometry and vibrational frequencies of the gas-phase HF-dimethyl ether complex were obtained using quantum-chemical methods. Equilibrium and vibrationally averaged geometries, harmonic and anharmonic wavenumbers of the complex were calculated using second-order perturbation theory procedures with B3LYP, B2PLYP-D and MP2 methods with 6-311++ G(2df, 2pd) basis set. Quantum-mechanical model describing anharmonic-type vibrational couplings within hydrogen bond was used to explain broadening, fine structure and temperature dependence of the F-H stretching IR absorption bands as effect of hydrogen bond formation. Simulations of the rovibrational structure of the F-H stretching bands were performed for different temperatures. The results were compared with experimental spectra.