Anodic Coupling of Diphenylbenzo[<i>k</i>]fluoranthene: Mechanistic and Kinetic Studies Utilizing Cyclic Voltammetry and Electrogenerated Chemiluminescence
作者:Jeff D. Debad、Jonathan C. Morris、Philip Magnus、Allen J. Bard
DOI:10.1021/jo961448e
日期:1997.2.1
followed using this technique. Cyclic voltammograms of 1 have been digitally simulated to provide mechanistic and kinetic insight into the initial intermolecular oxidative coupling reaction. Evidence supports an EC(2)()EE mechanism, in which the coupling of radical cations of 1 is the rate-limiting step. A second-order rate constant of k = 7500 M(-)(1) s(-)(1) has been determined for the dimerization process
在铂电极上氧化后,(7,12-二苯基)苯并[k]荧蒽(1)进行分子间脱氢偶联以形成双-4,4'-(7,12-二苯基)苯并[k]荧蒽(2) 。该产物的进一步氧化导致分子内偶联反应缓慢得多,从而产生二苯并[f,f']-4,4',7,7'-四苯基}二茚基[1,2,3-cd:1',2 ',3'-lm] per(3)。2可以通过1的本体电解合成,也可以通过4-溴-7,12-二苯基苯并[k]荧蒽(4)与镍催化剂的化学偶联来合成。化合物1-3能够进行电化学发光(ECL),并且已检测到它们的偶联反应,并使用此技术进行跟踪。已对1的循环伏安图进行了数字模拟,以提供有关初始分子间氧化偶联反应的机理和动力学见解。证据支持EC(2)()EE机制,其中自由基1的耦合是限速步骤。通过将实验数据拟合至理论工作曲线,已确定二聚过程的k = 7500 M(-)(1)s(-)(1)的二阶速率常数。