Spectroelectrochemical approach for analysing the reaction kinetics of N,N-dimethyl-<i>p</i>-anisidine cation radical with the neutral molecule in acetonitrile

Abstract

The decay reactions of N, N-dimethyl-<i>p</i>-anisidine (DMA) cation radical (DMA^'+) in acetonitrile (AN) have been analysed using an electron transfer stopped-flow (ETSF) method. In the ETSF method, DMA^'+ is generated by mixing acetonitrile solutions of DMA and tris(<i>p</i>-bromophenyl)amine cation radical (TBPA^'+). While DMA^'+ is fairly stable without DMA, the decay reacti ons of DMA^'+ have been observed when DMA remained in a large excess with DMA'+ in acetonitrile. Such promotion of the decay reaction is similar to the reactions of N,N-dimethyl-<i>p</i>-toluidine (DMT) cation radical (DMT^'+), which we have analysed previously. The rate law determined for the reaction of DMA^'+ with DMA, <i>-d</i>[DMA^'+]/dt<i> </i>= <i>k</i> [DMA^'+] [DMA] <i>(k </i>=8.05 <i>M</i>^-1<i> </i>s^-1), indicates that the reaction mechanism is similar to that of DMT^'+. By analysing the reactions of DMA^'+ with pyridine, it has been confirmed that the reaction mechanism proceeds via the acid -base interaction.