title: Photochemical properties of Yt base in aqueous solution.
abstract: Photoreactivity of Yt base [I] has been studied in aqueous solution [pH approximately 6] saturated with oxygen. Two photoproducts (II,III], resulting from irradiation at lambda = 253.7 nm and lambda greater than or equal to 290 nm, were isolated and their structures determined. The quantum yield for Yt base disappearance [zeta dis] is 0.002 [lambda = 313 nm]. It was shown that dye-sensitized photooxidation of Yt base in aqueous solution occurs according to a Type I mechanism, as well as with participation of singlet state oxygen. Quantum yields, fluorescence decay times and phosphorescence of Yt base have been also determined.
mesh_terms: D006147:Guanine / Q000031:analogs & derivatives*; D008163:Luminescent Measurements; D010777:Photochemistry; D011688:Purinones; D012343:RNA, Transfer; D013056:Spectrophotometry, Ultraviolet
chemical_list: D011688:Purinones; C012099:wye; D006147:Guanine; D012343:RNA, Transfer