均苯四甲酸二酰亚胺在分子供体-受体二元体或三元体中的电子受体单元或电子载体的众多应用中并不像可推测的那样具有化学活性。类似于相应的邻苯二甲酰亚胺,电子激发的均苯四甲酸二酰亚胺通过分子间电子转移(PET)过程氧化水溶液中的烷基羧酸盐,最终产生了激进-激进的组合产品,例如,N的苄基化产物6,N'-二甲基均苯四甲酸二酰亚胺5.用新戊酸作为叔丁基自由基源形成类似的产物7。从烷基化/脱芳构化和多次自由基添加中分离出一个额外的产物8。分别,经过长时间的照射。在分子内版本中,从N-羧烷基化均苯四甲酸二酰亚胺9a-e(C1至C5-间隔),检测到降解过程,例如,来自GABA底物9c的环化产物10。与邻苯二甲酰亚胺光化学形成鲜明对比,绿色均苯四甲酸二酰亚胺自由基阴离子在这里通过UV-vis吸收(λabs=720nm)检测,EPR(从9d开始),和几个分子内电子转移实例的NMR光谱。只有黄色的1,4-奎二醛结构是由分子间PET形成的,这是从吸收光谱(λabs=440nm)和随后的化学推断的。苯四胺自由基阴离子在室温下在黑暗中存活数小时,但在光化学反应条件下进一步降解。
Pyromellitic acid diimides are not as chemically unreactive as conjecturable (and presupposed) from their numerous applications as electron acceptor units or electron carriers in molecular donor-acceptor dyads or triads. Similar to the corresponding phthalimides, electronically excited pyromellitic diimides oxidize alkyl carboxylates in aqueous solution via intermolecular electron transfer (PET) processes, which eventually results in radical-radical combination products, e.g., the benzylation product 6 from N,N\'-dimethyl pyromellitic diimide 5. The analogous product 7 was formed with pivalic acid as tert-butyl radical source. One additional product 8 was isolated from alkylation/dearomatization and multiple radical additions, respectively, after prolonged irradiation. In intramolecular versions, from N-carboxyalkylated pyromellitic diimides 9a-e (C1 to C5-spaced), degradation processes were detected, e.g., the cyclization products 10 from the GABA substrate 9c. In sharp contrast to phthalimide photochemistry, the green pyromellitic diimide radical anion was detected here by UV-vis absorption (λabs = 720 nm), EPR (from 9d), and NMR spectroscopy for several intramolecular electron transfer examples. Only the yellow 1,4-quinodial structure is formed from intermolecular PET, which was deduced from the absorption spectra (λabs = 440 nm) and the subsequent chemistry. The pyromellitimide radical anion lives for hours at room temperature in the dark, but is further degraded under photochemical reaction conditions.