Fluorescence from the Second Excited Singlet State and Radiationless Processes in Pyrene Vapor
Fluorescence from the Second Excited Singlet State and Radiationless Processes in Pyrene Vapor
复制标题
第二激发单线态荧光和芘蒸气中的无辐射过程
DOI：
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发表时间：
1971
期刊：
影响因子：
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通讯作者：
K. Chihara
中科院分区：
文献类型：
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作者：
H. Baba;A. Nakajima;Masakatsu Aoi;K. Chihara
本文研究了芘在170℃、0.21 mm Hg气相中第二激发态S2的荧光光谱，特别注意了发射特性随激发能的变化。无论激发能如何，第一激发单重态S1的荧光量子产率Φ1F相对恒定（在0.14 ~ 0.08之间）。与此相反，S2荧光的量子产率Φ2F随着激发进入更高的单重态而迅速增加。激发到S2的比值Φ2F/Φ1F为0.001数量级，而激发到第四激发单重态S4的比值大于0.1。在芘蒸气中加入环己烷作为惰性外来气体，可使Φ2F/Φ1F显著降低，在环己烷高压（bbb60 mm Hg）下，该值似乎达到恒定值。通过对实验数据的分析和对辐射过程和无辐射过程动力学的考虑。
The fluorescence spectrum originating from the second excited singlet state S2 of pyrene in the vapor phase at 170°C and 0.21 mm Hg has been studied with particular attention to changes of emission characteristics with the excitation energy. The fluorescence from the first excited singlet state S1 has a comparatively constant quantum yield Φ1F (between 0.14 and 0.08), regardless of the excitation energy. In contrast to this, the quantum yield Φ2F of the fluorescence from S2 increases rapidly with excitation into successively higher singlet states. The ratio Φ2F/Φ1F is of the order of 0.001 for excitation into S2, but it is larger than 0.1 for excitation into the fourth excited singlet state S4. Addition of cyclohexane as an inert foreign gas to the pyrene vapor results in a marked decrease in Φ2F/Φ1F, which seems to reach a constant value at high pressures of cyclohexane (〉60 mm Hg). From an analysis of the experimental data and a consideration of the kinetics of radiative and radiationless processes in a...