Photochemical Ring-Opening Reaction in 2(1H)-Pyrimidinones: A Matrix Isolation...

• Autor(es): Lapinski, Leszek ; Rostkowska, Hanna ; Khvorostov, Artem ; Fausto, Rui ; Nowak, Maciej J.
• Data: 2003
• Identificador Persistente: http://hdl.handle.net/10316/10678
• Origem: Estudo Geral - Universidade de Coimbra
• Tipo de Documento: Artigo
• Idioma: Inglês

Descrição

Photoreactions induced by UV-B (290−320 nm) irradiation were studied for 1-methyl-2(1H)-pyrimidinone and 1-methylcytosine monomers isolated in low-temperature inert gas matrixes. A Norrish type I α-cleavage reaction leading to open-ring conjugated isocyanate was observed for 1-methyl-2(1H)-pyrimidinone. The structure of the photoproduct was identified by comparison of its experimental IR spectrum with the spectrum theoretically calculated at the DFT(B3LYP)/6-31++G(d,p) level. The main indication of isocyanate as a photoproduced species was the appearance in the infrared spectrum recorded after UV irradiation of a very strong band at a characteristic frequency of 2263 cm-1. Observation of a new band at nearly the same frequency in the spectrum of UV-irradiated monomeric 1-methylcytosine may suggest that also in the case of this compound a conjugated isocyanate is photoproduced. http://dx.doi.org/10.1021/jp035155i