DELAYED THERMAL FLUORESCENCE OF ANTHRAQUINONE IN SOLUTIONS
DELAYED THERMAL FLUORESCENCE OF ANTHRAQUINONE IN SOLUTIONS
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DOI：
10.1021/ja00751a003
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发表时间：
1971-01-01
影响因子：
15
通讯作者：
HERCULES, DM
中科院分区：
文献类型：
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作者：
CARLSON, SA;HERCULES, DM
蒽醌 (AQ) 在氟利昂中在 25°C 时发出的光由两组发射带组成。较长波长的发射是磷光，以前仅在 77 K 的冷冻玻璃中观察到。短波长发射是延迟热荧光 (DTF)，在冷却到 77 K 时消失。AQ 中 DTF 的出现通过 log (/) 与 1¡ T 的关系图得到证实。这些是线性的，斜率等于 AQ 中的 ST 分裂 (1400 cm-1)。此外，tdft 和 的值取决于存在的猝灭剂（例如氧气）的量，但对于给定的溶液，它们是相等的。这与通过 TT 吸收的闪光光解研究测量的 AQ 三重态的寿命一致。对于 25 C 下氟利昂中的 AQ， 和 分别为 0.057±0.011 和 0.037±0.008。开发了 AQ 激发态的稳态模型，该模型解释了从未报道过在流体溶液中发出荧光的化合物 (< 0.0005) 的 DTF 产率接近 6%。显示DTF是由热激活的TS交叉产生的，其速率比三联体失活的速率至少大101 2 3 。稳态模型还表明，早期对 AQ 光还原的猝灭和量子产率研究不足以将 AQ 三重态指定为光反应态。
The luminescence of anthraquinone (AQ) in Freon at 25 C consists of two sets of emission bands. The emission at longer wavelengths is phosphorescence, which has previously been observed only in frozen glasses at 77 K. The short-wavelength emission is delayed thermal fluorescence (DTF), which disappears upon cooling to 77 K. The occurrence of DTF in AQ is confirmed by plots of log (/) vs. 1¡ T. These are linear with a slope equal to the ST split (1400 cm-1) in AQ. In addition, values of tdft and depend on the amount of quencher present, such as oxygen, but they are equal for a given solution. This agrees with the lifetime of the AQ triplet, as measured by flash photolysis studies of TT absorption. For AQ in Freon at 25 C, and are 0.057±0.011 and 0.037±0.008, respectively. A steady-state model for the AQ excited states was developed that explains the nearly 6% yield of DTF for a compound never reported to fluoresce in fluid solution (< 0.0005). DTF is shown to result from thermally activated TS crossing having a rate at least 101 2 3greater than that of deactivation from the triplet. The steady-state model also shows that earlier quenching and quantum yield studies on AQ photoreduction are insufficient toassign the AQ triplet as the photoreactive state.