Solvent effect on the deactivation processes of benzophenone ketyl radicals in the excited state
Solvent effect on the deactivation processes of benzophenone ketyl radicals in the excited state
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DOI：
10.1021/jp060129g
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发表时间：
2006-10-26
影响因子：
2.9
通讯作者：
Majima, Tetsuro
中科院分区：
文献类型：
--
作者：
Sakamoto, Masanori;Cai, Xichen;Majima, Tetsuro
研究了溶剂对二苯甲酮衍生物（BPD）激发态（BPDH）自由基的影响。（D-1）进行了调查。BPDH的吸收光谱和荧光光谱。(D-1)使用纳秒-皮秒双色双激光闪光光解测量在各种溶剂中的光吸收。来自BPDH的荧光峰，(D-1)显示出由于与溶剂分子的偶极-偶极相互作用而产生的位移。BPDH的偶极矩（mu（e））。(D-1)估计为7-10 D，表明BPDH. (D-1)是高度极化的。结果表明，荧光寿命（τ（f））取决于μ（e）在乙腈中，因为溶剂分子的稳定性影响τ（f）值在极性溶剂中，占主导地位。相反，BPDH的构象。(D-1)在环己烷中起重要作用，因为BPDH的单分子反应的效率。(D-1)取决于构象。取代基对BPDH电子转移的影响。(D-1)与母体分子的相互作用。
The solvent effects on ketylradicals of benzophenone derivatives (BPD) in the excited state (BPDH.(D-1)) were investigated. Absorption and fluorescence spectra of BPDH.(D-1) in various solvents were measured using nanosecond-picosecond two-color two-laser flash photolysis. The fluorescence peaks from BPDH.,(D-1) showed a shift due to the dipole-dipole interaction with the solvent molecules. The dipole moments (mu(e)) of BPDH.(D-1) were estimated to be 7-10 D, indicating that BPDH.(D-1) are highly polarized. It was revealed that the fluorescence lifetime (tau(f)) depends on mu(e) in acetonitrile because the stabilization by solvent molecules affects the tau(f) value in polar solvents, predominantly. On the contrary, the conformation of BPDH.(D-1) plays an important role in cyclohexane because the efficiency of the unimolecular reaction from BPDH.(D-1) depends on the conformation. The substituent effect on the electron transfer from BPDH.(D-1) to their parent molecules was also discussed.