Utilization of stable isotopes for the study of vibrational spectra of furaldehydes

Photoisomerization and Photochemistry of Matrix-Isolated 3-Furaldehyde

“…The first synthetic procedure to obtain 3FA was reported as early as in 1932 . 3FA, as well as its structural isomer 2-furaldehyde (2FA; also known as furfural), have been the subject of many experimental and theoretical studies in the 1970s and 1980s. − 3FA and 2FA have been found to exist in the gas phase, nematic and isotropic solutions, and neat liquid state, as a mixture of two planar conformers differing by rotation of the aldehyde group around the exocyclic C−C bond (cis and trans with respect to the ring oxygen atom; see Scheme ). − For 2FA, the trans conformer was found to be the lowest energy form, with gas phase reported values for Δ E (cis−trans) ranging from 3.10 to 8.79 kJ mol −1 , − which implies a minimum expected population of the conformational ground state of 2FA at room temperature (RT) of ca. 80%.…”

“…Vibrational spectra of 3FA were studied mainly in condensed phases in the region of the carbonyl stretching vibration. ,, These studies have also indicated the existence of two planar conformers differing by internal rotation of the aldehyde group. The experimental observation of these two conformers has been reported by Volka et al, through the analysis of the aldehyde C−H and CO stretching regions of the infrared spectra of the compound and some of its isotopomers in the gas phase and in CCl 4 solution.…”