High-Pressure Study on the Quenching Mechanism by Oxygen of the Lowest Triplet State in Solution
High-Pressure Study on the Quenching Mechanism by Oxygen of the Lowest Triplet State in Solution
复制标题
溶液中最低三重态氧淬火机理的高压研究
DOI：
10.1021/jp983144x
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发表时间：
1998
影响因子：
2.9
通讯作者：
S. Hirayama
中科院分区：
文献类型：
--
作者：
M. Okamoto;Fujio. Tanaka;S. Hirayama
研究了在压力高达 400 MPa 的五种饱和烃溶剂中，9-乙酰蒽（ACA）的最低三重态（T1）被氧气猝灭的机理。 ACA T1 态的淬灭速率常数 kqT 随着压力的增加单调减小，kqT 的表观活化体积在 0.8−5.3 cm3/mol 范围内变化。还发现 ln kqT 与 ln η 的关系图（其中 η 是溶剂粘度）在所有检查的溶剂中都显示出显着的向下曲率。根据 0.1 MPa 下时间分辨热透镜的测量，以及作为压力函数的三重态-三重态吸收光谱的测量，发现 ACA T1 态的产率在所检查的实验条件下近似一致。 9,10-二甲基蒽 (DMEA) 的范德华半径几乎等于 ACA 的最低激发单线态 (S1) 的氧的猝灭速率常数 kqS 随着压力的增加而急剧下降，a...
The mechanism for the quenching by oxygen of the lowest triplet state (T1) of 9-acetylanthracene(ACA) in five saturated hydrocarbon solvents at pressures up to 400 MPa was investigated. The quenching rate constants of the T1 state of ACA, kqT, decrease monotonically with increasing pressure, and the apparent activation volumes for kqT vary in the range 0.8−5.3 cm3/mol. It was also found that the plots of ln kqT against ln η, where η is solvent viscosity, show significant downward curvatures in all the solvents examined. From measurements by the time-resolved thermal lensing at 0.1 MPa, together with measurements of triplet−triplet absorption spectra as a function of pressure, the yields of the T1 state of ACA were found to be approximately unity in the experimental conditions examined. The quenching rate constants, kqS, by oxygen of the lowest excited singlet state (S1) of 9,10-dimethylanthracene (DMEA) whose van der Waals radius is nearly equal to that of ACA decrease strongly with increasing pressure, a...