Infrared spectra of p-, m- and o-fluorobenzaldehyde in low temperature argon matrices

✍ Scribed by Takao Itoh; Nobuyuki Akai; Keiichi Ohno

• Publisher: Elsevier Science
• Year: 2006
• Tongue: English
• Weight: 191 KB
• Volume: 786
• Category: Article
• ISSN: 0022-2860
• DOI: 10.1016/j.molstruc.2005.10.020

✦ Synopsis

Three structural isomers of fluorobenzaldehyde (p-, m-and o-forms) have been investigated in detail with matrix-isolation infrared spectroscopy, in the 700-3000 cm K1 region, combined with the UV photoexcitation and the density functional calculations. Two rotamers (syn and anti) were identified for m-and o-fluorobenzaldehyde upon the photoexcitation and most of the bands of each rotamer were assigned. It is shown that the formation of the intramolecular C-H/F hydrogen bond for the anti rotamer of o-FB results in the shortening of the aldehyde C-H bond length and that the C-F and/or CaO bond lengths are shortened for the syn rotamer of o-FB presumably due to the repulsion between the aldehyde O and F atoms.