Photodissociation and collision-induced dissociation of molecular ions from methylphenol and chloromethylphenol

✍ Scribed by C. J. Cassady; S. Afzaal; B. S. Freiser

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 601 KB
• Volume: 29
• Category: Article
• ISSN: 1076-5174
• DOI: 10.1002/oms.1210290106

✦ Synopsis

The photodissociation of molecular ions from a series of methylphenols and chloromethylphenols was studied using Fourier transform ion cyclotron resonance mass spectrometry (FTMS). The photodissociation spectra contain both UV and visible absorption maxima. The positions of these bands correlate well with solution electronic absorption spectra and photoelectron spectra, respectively, suggesting that photodissociating populations of the molecular ions have not rearranged. The molecular ion of benzyl alcohol can be readily distinguished from the isomeric 2and Cmethylphenol ions on the basis of the position and intensity of the photodissociation bands, and the identity of the photoproduct. The p-chlorophenol isomers, 4-chloro-2-methylphenol and 4-chloro-3-methylphenol, cannot be distinguished by their photodissociation spectra. Minor differences exist between these spectra and that of the o- chlorophenol isomer Z-chIoro-5-methylpheno1, suggesting that the relative positions of the chloro and hydroxy groups may have a greater effect on photodissociation than the position of the methyl group. For comparison, low-energy collision-induced dissociation using FTMS was also performed on the same ions. ~