Reductions with SmI2: mechanistic probe for distinguishing between two operational modes of proton transfer
作者:Alexander Tarnopolsky、Shmaryahu Hoz
DOI:10.1039/b713014g
日期:——
is linear with a slope smaller than one. Detailed analysis shows that a curved log-log plot such as for H(2)O and MeOH is indicative of a major contribution by protonation within an ion pair of the radical anion and Sm(+3) complexed to a variable number of proton donor molecules, whereas a linear plot is a result of protonation from the bulk solution.
在四个质子供体:H(2)O,MeOH,i-PrOH和三氟乙醇(TFE)的存在下,研究了在THF中用SmI(2)还原1,1-二芳基-2,2-二氰基乙烯的方法。在质子供体浓度低的情况下,前两个动力学顺序几乎一致,在高浓度时,动力学顺序接近四个,而对于i-PrOH和TFE,对数-对数图是线性的,斜率小于1。详细的分析显示,诸如H(2)O和MeOH的对数对数曲线表示通过与可变数量的质子供体络合的自由基阴离子和Sm(+3)的离子对内的质子化作用,表明了主要贡献分子,而线性图是从本体溶液质子化的结果。