Heihoff K, Redmond R W, Braslavsky S E, Rougée M, Salet C, Favre A, Bensasson R V
Max-Planck-Institut für Strahlenchemie, Mülheim a.d. Ruhr, W. Germany.
Photochem Photobiol. 1990 Jun;51(6):635-41.
The quantum yield of triplet formation, phi T, and that of the photosensitized formation of singlet molecular oxygen, phi delta, were determined for a rare nucleoside, 4-thiouridine (4t-Urd), in water and in acetonitrile, using singlet molecular oxygen phosphorescence, laser-induced optoacoustics and time-resolved thermal lensing. These yields, phi T and phi delta, the latter in aerated solutions, were found to be, respectively, in water: 0.67 +/- 0.17 and 0.18 +/- 0.04 and in acetonitrile: 0.61 +/- 0.15 and 0.50 +/- 0.20. The fraction of the 4t-Urd triplet molecules quenched by oxygen leading to singlet molecular oxygen, S delta, was calculated to be between 0.7 and unity in both solvents, this value being indicative of a pi pi*character for the lowest triplet state of 4t-Urd.
利用单线态分子氧磷光、激光诱导光声和时间分辨热透镜技术，测定了稀有核苷4-硫尿苷（4t-Urd）在水和乙腈中的三重态形成量子产率φT以及单线态分子氧的光敏化形成量子产率φδ。发现在水中，这些产率（φT和φδ，后者为通气溶液中的产率）分别为0.67±0.17和0.18±0.04；在乙腈中分别为0.61±0.15和0.50±0.20。计算得出，在两种溶剂中，被氧猝灭生成单线态分子氧的4t-Urd三重态分子的比例Sδ在0.7到1之间，该值表明4t-Urd最低三重态具有ππ*特征。
