Investigation of hydrogen bond in binary mixture (pyridine + propionic acid) by spectroscopy and DFT calculations

► Model of Electronic Behavior interpreted the blue shift of the ring breathing mode. ► The line shape of pyridine's ring breathing and triangle mode were discussed. ► We optimized the hydrogen-bonded clusters by DFT and obtained the spectral features. ► We discussed the effect of the hydrogen bond on Fermi Resonance.