Phosphorescence spectra of benzophenone in aqueous acetate solutions at 77 K. Relevance to the determination of pK(T1) of benzophenone
Phosphorescence spectra of benzophenone in aqueous acetate solutions at 77 K. Relevance to the determination of pK(T1) of benzophenone
复制标题
77 K 乙酸盐水溶液中二苯甲酮的磷光光谱。与二苯甲酮 pK(T1) 测定的相关性
DOI：
10.1021/j100490a021
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发表时间：
1978
期刊：
影响因子：
--
通讯作者：
A. Szabo
中科院分区：
文献类型：
--
作者：
D. Rayner;P. K. Tolg;A. Szabo
引言 根据激光闪光实验中观察到的瞬态的初始强度和寿命的测量结果，通过直接测定，质子化二苯甲酮的三重态 pK 值 (pKCI?!) 已显示为 1.5。 2 该值与三重态 B 和 BH+ 物质的特征寿命（分别为 4 和 6.2 X 10~ 8 s）的差异很大的值相结合，令人满意地解释了水溶液中观察到的磷光随着酸度增加到 pH 5 而消失的情况3、4。最近，Favaro 和 Bufalini5 报道了使用发光敏化技术对室温下水溶液中三重态二苯甲酮的行为进行的研究技术。他们的寿命和 pK 值结果与直接激光闪光技术非常一致。然而，他们提出导致磷光下降的激发态反应并不是简单的酸碱平衡
Introduction The triplet state pK value, pKCI?!), of protonated benzophenone has been shown to be 1.5 by a direct de-termination based upon measurements of the initial in-tensities and lifetimes of the transients observed in laser flash experiments. 2 This value coupled with the widely different values found for the characteristic lifetimes of the triplet B and BH+ species (4 and 6.2 X 10~ 8 s, re-spectively) satisfactorily explains the disappearance of the phosphorescence observed in aqueous solution3, 4 as the acidity increases through pH 5. Recently Favaro and Bufalini5 have reported an investigation of the behavior of triplet benzophenone in aqueous solution at room temperature using a luminescence sensitization technique. Their results, for lifetimes and pK value, are in very good agreement with the direct laser flash technique. However they propose that the excited state reaction which causes the drop in phosphorescence is not the straightforward acid-base equilibrium