Effects of chloromethanes on the photoionization of methylphenothiazine in silica gels at room temperature
- Univ. of Houston, TX (United States)
Chloromethanes were added to silica gel of 14 nm pore size with methylphenothiazine (PC{sub 1}) trapped in them. The methylphenothiazine was photoionized by 320-nm irradiation by a one-photon process to form stable methylphenothiazine cation radical (PC{sub 1}{sup +}) which was detected by electron spin resonance. The addition of CCl{sub 4} or CHCl{sub 3} increases the net PC{sub 1}{sup +} photoyield when the samples are irradiated at room temperature while CH{sub 2}Cl{sub 2} and CH{sub 3}Cl have no effect. Thus, CHCl{sub 3} and CCl{sub 4} are suggested to act as better electron acceptors in competition with the silica gel framework while CH{sub 2}Cl{sub 2} and CH{sub 3}Cl do not seem to be able to compete with the silica gel framework. A chloromethane with more Cl atoms has a greater electron affinity which supports this interpretation. No effects of these chloromethanes on the net photoionization yield of PC{sub 1} in silica gels at 77 K were observed, probably due to the immobilization of the chloromethanes at 77 K. 21 refs., 7 figs.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 41628
- Journal Information:
- Langmuir, Journal Name: Langmuir Journal Issue: 3 Vol. 11; ISSN 0743-7463; ISSN LANGD5
- Country of Publication:
- United States
- Language:
- English
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