Knowledge Bank

Polarized Raman spectra are reported for the lattice vibrational region of single crystals of the diazines: pyrazine, pyrazine-$d4$, pyrimidine and pyrimidine-$d4$. The lattice region for polycrystalline pyridazine has also been investigated. Raman spectra as a function of temperature between approximately $100\circ K$ and $300\circ K$ are reported for all the crystals. Assignments are suggested based on the results of the polarization and deuterium substitution studies.