Photochemistry of radicals trapped in frozen methanol--water mixtures
Methanol--water mixtures were exposed to x-rays at 77$sup 0$K and the photochemistry and paths of conversion of the induced radicals were investigated by ESR methods. The main x-ray induced radical, the hydroxymethyl radical, is photolyzed by uv light to give CH$sub 3$ and CHO radicals and H atoms. The CHO radicals give rise to CH$sub 2$OH and H atoms when bleached by visible light and to another radical, possibly the methoxy radical, when annealed. Uv irradiation of this radical gives back CHO radicals and CH$sub 2$OH radicals. The methyl radicals give rise to CH$sub 2$OH radicals, and possibly also CHO radicals when decaying at 77$sup 0$K. The uv irradiation seems to cause photoionization of the hydroxymethyl radical. X-irradiation gives rise to somewhat different spectra in glassy and polycrystalline matrices. In the latter case a narrow ($delta$H = 3.4 +- 0.6 G) singlet spectrum is formed which is not seen in glassy matrices. This singlet may be due to electrons in shallow traps, since it is eliminated by the presence of an electron scavenger (H$sub 2$$O$$sub 2$). (auth)
- Research Organization:
- Norsk Hydro's Inst. for Cancer Research, Oslo
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-33-000122
- OSTI ID:
- 4146399
- Journal Information:
- J. Phys. Chem., v. 79, no. 21, pp. 2220-2224, Journal Name: J. Phys. Chem., v. 79, no. 21, pp. 2220-2224; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Detection of CH/sub 2/OH radicals by resonance-enhanced multiphoton ionization spectroscopy
Mercury-photosensitized production of free radicals in organic glasses