Photoreaction of Valerophenone in Aqueous Solution
Photoreaction of Valerophenone in Aqueous Solution
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DOI：
10.1021/jp981130l
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发表时间：
1998-06
影响因子：
2.9
通讯作者：
R. Zepp;M. M. Gumz-M.;A. L. Miller;H. Gao
中科院分区：
文献类型：
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作者：
R. Zepp;M. M. Gumz-M.;A. L. Miller;H. Gao
研究了水溶液中苯基酮-戊苯酮的光反应动力学和产物随温度、pH和波长的变化。在此条件下(~lt；10~(-4)M)，光反应对戊二酮的浓度为准一级反应。在2 90−330 nm光谱范围内，在10~40℃的温度范围内，光反应的第二类量子产率接近于1，裂解成苯乙酮和丙烯的量子产率为0.6 5±0.0 4，在2 0℃下环合成两个环丁醇的总量子产率为0.32±0.0 3，还生成了少量的1-苯基环戊醇(∼2%)。这些光反应可以通过加入三重态猝灭剂山梨醇或山梨酸来猝灭，并且斯特恩−伏尔默曲线至少有80%的猝灭是线性的。在稳态辐照猝灭研究的基础上，估算出二茂铁酮在20℃时的三重态寿命为52 ns，...
Kinetics and products of the photoreaction of the phenyl ketone valerophenone were investigated as a function of temperature, pH, and wavelength in aqueous solution. Under these conditions (<10-4 M), the photoreactions are pseudo-first-order with respect to valerophenone concentration. Type II quantum yields for photoreaction were close to unity throughout the 290−330 nm spectral region and in the temperature range from 10 to 40 °C. The quantum yields for the photoproducts were 0.65 ± 0.04 for cleavage to acetophenone and propene and an overall yield of 0.32 ± 0.03 for cyclization to two cyclobutanols at 20 °C. A small amount of 1-phenylcyclopentanol (∼2% yield) also was formed. These photoreactions were quenchable by additions of the triplet quenchers sorbic alcohol or sorbic acid, and Stern−Volmer plots were linear up to at least 80% quenching of the photoreactions. On the basis of quenching studies with steady-state irradiations, the triplet lifetime of valerophenone at 20 °C was estimated to be 52 ns,...