Direct observation of arylnitrene formation in the photoreaction of arylazide crystals.
Acta Crystallogr B
; 66(Pt 6): 639-46, 2010 Dec.
Article
en En
| MEDLINE
| ID: mdl-21099026
ABSTRACT
Seven crystal structures of arylazides, 2-azidobiphenyl (2), 4-(4-azidophenyl)butanoic acid (3), 3-azidobenzoic acid (4), N-(4-azidophenyl)acetamide (5), 2,4,6-trichlorophenyl azide (6), 2,5-dibromophenyl azide (7) and 2,4,6-tribromophenyl azide (8), have been analyzed by X-rays. When the crystals were irradiated with UV light at ≃ 80 K, only 2-azidobiphenyl gradually changed its cell dimensions with the retention of the single-crystal form. The crystal structure after photo-irradiation was analyzed by X-rays under the same conditions as those before photo-irradiation. Approximately 20% of the 2-azidobiphenyl molecule was converted to the triplet 2-biphenylnitrene and dinitrogen molecules. The existence of the triplet nitrene was confirmed by ESR and IR measurements. Although the structure of dinitrogen was clearly determined, the nitrene structure was obscure because the nitrene produced was almost superimposed on the original 2-azidobiphenyl. The other six crystals were non-reactive or easily broken when they were exposed to UV light. The different reactivity between 2-azidobiphenyl and the other compounds was successfully explained by the reaction cavity of the azido group.
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Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Acta Crystallogr B
Año:
2010
Tipo del documento:
Article
País de afiliación:
Japón