H-bonded complexes of 2-aminopyrimidine-parabenzoquinone in an argon matrix

The IR spectroscopy method was used to study H-bonded complexes of 2-aminopyrimidine NH₂Py with parabenzoquinon Qu in a low-temperature argon matrix. The IR absorption spectra of these compounds were obtained in the spectral range 400-3600 cm^-1 at various concentration ratios at T = 11 K. The molar integral absorption coefficients in the bands of stretching vibrations of the free and H-bonded NH₂ groups were determined. The quantum-mechanical calculations of the IR spectra of the NH₂Py and Qu molecules and their dimers were performed. Comparison of the experimental and calculated data suggests that the NH₂Py-Qu dimers in the argon matrix have a planar structure with two weak hydrogen bonds NH⋯O and CH⋯N.