Relationship between Molecular Structure and Electron Targets in the Electroreduction of Benzocarbazolediones and Anilinenaphthoquinones. Experimental and Theoretical Study
作者:N. Macías-Ruvalcaba、G. Cuevas、I. González、M. Aguilar-Martínez
DOI:10.1021/jo011083k
日期:2002.5.1
We report the synthesis and voltamperometric reduction of 5H-benzo[b]carbazole-6,11-dione (BCD) and its 2-R-substituted derivatives (R = -OMe, -Me, -COMe, -CF(3)). The electrochemical behavior of BCDs was compared to that of the 2-[(R-phenyl)amine]-1,4-naphthalenediones (PANs) previously studied. Like PANs, BCDs exhibit two reduction waves in acetonitrile. The first reduction step for the BCDs represents
我们报告了5H-苯并[b]咔唑-6,11-二酮(BCD)及其2-R-取代的衍生物(R = -OMe,-Me,-COMe,-CF(3))的合成和伏安还原。将BCD的电化学行为与之前研究的2-[((R-苯基)胺] -1,4-萘二酮(PANs))的电化学行为进行了比较。像PAN一样,BCD在乙腈中表现出两个还原波。BCD的第一个还原步骤表示自由基阴离子的形成,该步骤的半波电势(E(1/2))值比PAN的负值小。第二还原波,对应于二价对苯二酚的形成,具有E(1/2)值,该值移至更多的负电位。对于BCD,还获得了类似于PAN系列的良好线性Hammett-Zuman关系(E(1/2)vs sigma(p))。但是,与PAN不同,在BCD中,第一个还原波比第二个波更容易受到取代基的影响,这表明BCD中两个连续的单电子还原的顺序与PAN中的顺序相反。这是由于两个系统中的电子离域不同而引起的。对于BCD,则