作者:Marco Holzapfel、Christoph Lambert、Carola Selinka、Dietmar Stalke
DOI:10.1039/b204392k
日期:2002.8.27
The mixed-valence character of four bis(N,N-dihydrodimethylphenazine) radical cation derivatives with varying π-electron bridges was investigated. The electron transfer (ET) distance within these derivatives varies from ca. 12.5 Å for 1,2-bis[2-(5,10-dihydro-5,10-dimethylphenazinyl)]acetylene (1) to ca. 19.3 Å for 9,10-bis[2-(5,10-dihydro-5,10-dimethylphenazinyl)ethynyl]anthracene (4). All radical cation species show intense intervalence charge-transfer (IV-CT) bands in the NIR. The Mulliken–Hush analysis was used to derive the electronic coupling V, which ranges from 310 to 870 cm−1. Comparisons with analogous ET systems in which the dihydrodimethylphenazine redox centres have been replaced by triarylamine units show that the dihydrodimethylphenazine species have a significantly higher internal reorganisation
energy associated with the ET. This behaviour is attributed to C–N stretching and C–C ring modes of the dihydrodimethylphenazine units.
研究了具有不同 π 电子桥的四种双(N,N-二氢二甲基吩嗪)自由基阳离子衍生物的混价特性。这些衍生物内部的电子转移(ET)距离从 1,2-双[2-(5,10-二氢-5,10-二甲基吩嗪基)]乙炔(1)的约 12.5 Å 到 9,10-双[2-(5,10-二氢-5,10-二甲基吩嗪基)乙炔基]蒽(4)的约 19.3 Å 不等。所有自由基阳离子种类都在近红外光谱中显示出强烈的间隔电荷转移(IV-CT)带。利用 Mulliken-Hush 分析法得出了电子耦合 V,其范围在 310 到 870 cm-1 之间。与用三芳基胺单元取代二氢二甲基吩嗪氧化还原中心的类似 ET 系统进行比较后发现,二氢二甲基吩嗪物种与 ET 相关的内部重组能明显更高。这种行为归因于二氢二甲基吩嗪单元的 C-N 伸展和 C-C 环模式。