Structure, vibrational spectra and DFT characterization of the intra- and inter-molecular interactions in 2-hydroxy-5-methylpyridine-3-carboxylic acid – Normal modes of the eight-membered HB ring

Can far-IR action spectroscopy combined with BOMD simulations be conformation selective?

“…13 Additionally, intrinsic hydrogen bond vibrations can be directly probed in the far-IR region, 14,15 as previously shown for condensed phase systems using low-frequency FTIR spectroscopy. 16,17 In contrast, the mid-IR region can indirectly probe hydrogen bonds through frequency shifts of the amide vibrations. One more advantage of far-IR probing is the possibility to probe larger and more complex molecules.…”

A Combined theoretical and experimental study of conformational and spectroscopic profile of 2-acetamido-5-aminopyridine

“…The strong peak observed at 1367/1370 cm -1 in FTIR/FT Raman spectrum of 2A5AP compound with corresponding calculated wavenumber 1376 cm -1 is assigned to interesting umbrella mode (symmetric deformation) of CH 3 group vibrations which is generally observed in the range 1360-1390 cm -1 in pyridine derivatives [45,46]. In phase and out of phase asymmetric deformations of methyl group in title molecule are theoretically predicted at wavenumbers 1463 and 1446 cm -1 respectively with more than 75% of PED and observed as medium intense FT-Raman band at 1434 cm -1 also lies within the range 1400-1485 cm -1 as reported in literature [47].…”