Diffusion of electrically neutral radicals and anion radicals created by photochemical reactions
Diffusion of electrically neutral radicals and anion radicals created by photochemical reactions
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光化学反应产生的电中性自由基和阴离子自由基的扩散
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
and Masahide Terazima
中科院分区：
文献类型：
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作者：
K. Okamoto;N. Hirota;and Masahide Terazima
采用瞬态光栅（TG）方法研究了酮类化合物在酒精溶剂中光化学反应产生的中间自由基的扩散过程。通过控制氢氧化钠（NaOH）在酒精溶剂中的浓度，选择性地产生了苯乙酮、苯甲醛、山酮、二苯甲酮和苯甲酮的电中性自由基和阴离子自由基。在相同的条件下，可以成功地测量阴离子自由基、中性自由基和母体稳定分子的平动扩散常数D。发现中性和阴离子自由基的扩散速度都比母体分子慢。在较宽的溶剂粘度、溶质尺寸和温度范围内，详细比较了阴离子自由基、中性自由基和母体分子的D值。在任何条件下，带电自由基的D值与中性自由基的D值相似。根据自由基的分子间电荷极化率讨论了这种相似性的可能来源。
Diffusion processes of the intermediate radicals created by the photochemical reactions of ketones in alcoholic solvents are investigated by using the transient grating (TG) method. The electrically neutral radicals and the anion radicals of acetophenone, benzaldehyde, xanthone, benzophenone and benzil were created selectively by controlling the concentration of sodium hydroxide (NaOH) in alcoholic solvents. The translational diffusion constants (D) of the anion radicals, the neutral radicals, and the parent stable molecules can be successfully measured under the same conditions by this method. It is found that both the neutral and anion radicals diffuse slower than the parent molecules. Values of D of the anion radicals, the neutral radicals and the parent molecules are compared in detail in wide ranges of solvent viscosities, solute sizes and temperatures. Under any conditions, D values of the charged radicals are similar to those of the neutral radicals. A possible origin of such a similarity is discussed in term of the intermolecular charge polarizabilities of the radicals.