Unravelling the ultrafast photodecomposition mechanism of dibenzoyl peroxide in solution by time-resolved IR spectroscopy.
Unravelling the ultrafast photodecomposition mechanism of dibenzoyl peroxide in solution by time-resolved IR spectroscopy.
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通过时间分辨红外光谱揭示溶液中过氧化二苯甲酰的超快光分解机理。
DOI：
10.1039/b718501d
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
D. Schwarzer
中科院分区：
文献类型：
--
作者：
C. Reichardt;J. Schroeder;P. Vöhringer;D. Schwarzer
利用飞秒紫外光激发和中红外宽带探测脉冲研究了过氧化二苯甲酰（DBPO）的超快光裂解过程，探讨了其解离机理.借助于（13）C-标记的DBPO，可以明确地将指纹区域中的瞬态IR谱带归属于苯甲酰氧基自由基。我们的实验表明，裂解受DBPO的S（1）寿命控制，在0.4 ± 0.2 ps内，通过O-O键和苯基-C（羰基）键的协同断裂，产生苯甲酰氧基/苯基自由基对和CO（2）。20%的自由基对在70 ps的时间尺度上成对地重组为苯甲酸苯酯。
The ultrafast photo-fragmentation of dibenzoyl peroxide (DBPO) is studied using femtosecond UV excitation at 266 nm and mid-infrared broadband probe pulses to elucidate the dissociation mechanism. With the help of (13)C-labeled DBPO it was possible to unambiguously assign transient IR bands in the fingerprint region to the benzoyloxy radical. Our experiments show that the fragmentation is controlled by the S(1)-lifetime of DBPO and within 0.4 +/- 0.2 ps leads to a benzoyloxy/phenyl radical pair plus CO(2)via concerted bond breakage of the O-O and the phenyl-C(carbonyl) bond. 20% of the radical pairs geminately recombine to phenyl benzoate on a timescale of 70 ps.