Kinetics of fullerene triplet states
Kinetics of fullerene triplet states
复制标题
富勒烯三重态动力学
DOI：
10.1163/156856797x00178
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
R. Weisman
中科院分区：
文献类型：
--
作者：
K. Ausman;R. Weisman
研究描述其目标是富勒烯三重态弛豫的定量动力学描述。溶液相T1 C60和C70的室温本征寿命差异很大，甲苯中的值分别为143 μs和12 ms。这些衰减率在室温附近仅表现出弱的温度依赖性。T1 C60的本征寿命在1000 K以下与振动能含量有简单的依赖关系。有效的三重态-三重态湮灭发生在C60和C70溶液中，在约。扩散限制速率的50%。在混合溶液中，观察到C60和C70之间以及C60和（CH 3）2C 60之间的快速可逆三重态能量交换。一种新的方法来测量相对三重态熵和熵在这种混合物也已被应用。复杂的动力学已被发现在C70的解决方案和建模的可逆形成的短寿命的三重态准分子，占有效的自淬灭。C60的自猝灭与温度有很大关系，但其机理尚未解决。
Studies are described whose goal is a quantitative kinetic description of fullerene triplet relaxation. The room-temperature intrinsic lifetimes of solution phase T1 C60 and C70 differ substantially, with values in toluene of 143 μs and 12 ms, respectively. These decay rates exhibit only weak temperature dependence near room temperature. The intrinsic lifetime of T1 C60 has a simple dependence on vibrational energy content up to 1000 K. Efficient triplet-triplet annihilation occurs in C60 and C70 solutions at ca. 50% of the diffusion-limited rate. In mixed solutions, rapid reversible triplet energy exchange was observed between C60 and C70, and between C60 and (CH3)2 C60. A new method for measuring relative triplet enthalpies and entropies in such mixtures has also been applied. Complex kinetics has been uncovered in C70 solutions and modeled by reversible formation of shortlived triplet excimers, accounting for the efficient self-quenching. C60 self-quenching has been found to be highly temperature dependent, but the mechanism remains unresolved.