Unusual behavior of the pyrimidine–2-hydroxypyrimidine heterodimer isolated in argon matrices

We have applied low-temperature matrix-isolation IR spectroscopy to study the structures of the pyrimidine–2-hydroxypyrimidine and pyrimidine–phenol heterodimers isolated in low temperature argon matrices. IR spectra are registered for samples with different relative concentrations of the heterodimer components. Based on the measured IR intensities of the spectral bands of the monomer molecules and their heterodimers the presence of the OH⋯N hydrogen bond in the pyrimidine–phenol complex isolated in argon matrices is demonstrated. However this bond is not observed in the pyrimidine–2-hydroxypyrimidine complex.