Effects of hydrogen bonding on the ring breathing mode of pyridine in pyridine/chloroform and pyridine/bromoform systems

Hydrogen bonding between pyridine and chloroform as well as pyridine and bromoform is studied using noisy light-based coherent anti-Stokes Raman scattering (I(2)CARS). A blue-shift in the ring breathing mode of pyridine is observed when a hydrogen bond complex is formed between the nitrogen on pyridine and the hydrogen from the donor molecule. The formation of the hydrogen bond between haloforms and pyridine is very weak and does not result in an independent peak. Nonetheless, data analysis allows for identification of a small blue-shift of the hydrogen bonded complex.