Comparative Study on Decomposition Rate Constants for Some Alkoxyamines
Comparative Study on Decomposition Rate Constants for Some Alkoxyamines
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几种烷氧基胺分解速率常数的比较研究
DOI：
10.1021/ma011760c
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发表时间：
2002
期刊：
影响因子：
5.5
通讯作者：
T. Fukuda
中科院分区：
文献类型：
--
作者：
A. Goto;Y. Kwak;C. Yoshikawa;Y. Tsujii;Y. Sugiura;T. Fukuda
测定了一些烷氧基胺的分解速率常数 k dec 以及活化速率常数 k act 并对其结构进行了比较。结果表明，分解主要取决于空间因素，而空间因素和极性因素都会影响 k act 。大体积的硝基氧不太容易分解，可能是由于该反应中空间拥挤的过渡态。从机理上讲，分解被证明是双分子发生的。 （即，单分子途径是微不足道的。）还发现烷氧基胺在失活阶段比在活化阶段更容易发生分解。
The decomposition rate constants k dec as well as the activation rate constants k act of some alkoxyamines were determined and compared with regard to their structures. The results showed that decomposition depends predominantly on steric factors, while both steric and polar factors affect k act . Bulky nitroxides are less susceptible to decomposition probably due to the sterically congested transition state in this reaction. Mechanistically, decomposition was demonstrated to occur bimolecularly. (Namely, the unimolecular pathway is insignificant.) It was also found that alkoxyamines have more chances to undergo decomposition at the deactivation stage than at the activation stage.