Hydrogen-bonded complexes of 2-aminopyrimidine–parabenzoquinone in an argon matrix

Abstract

The H-bonded complexes of 2-aminopyrimidine (NH2Py) with parabenzoquinone (Qu) in a low-temperature argon matrix are investigated by the method of IR spectroscopy. The IR absorption spectra in the spectral range 400–3600cm−1 are obtained for different concentration ratios of these compounds at a temperature of 11K. The molar integrated absorption coefficients in the bands of the stretching modes of the free and H-bonded NH2 group are determined. Quantum-mechanical calculations of the IR spectra of the NH2Py and Qu molecules and their dimers are carried out. A comparison of the experimental and calculated results permits the conclusion that NH2Py–Qu dimers in an argon matrix have a planar structure with two weak hydrogen bonds, NH⋯O and CH⋯N.