Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, 44801, Bochum, Germany.
Chem Commun (Camb). 2022 Jul 28;58(61):8484-8487. doi: 10.1039/d2cc03065a.
Simple imines and diimines are common building blocks in organic synthesis, but the compound class is spectroscopically not well characterized. Herein we report the formation of the simplest diimine, namely 1,2-diiminoethane, as well as spectroscopic characterization by cryogenic matrix isolation IR and UV/Vis spectroscopy. Three conformers of 1,2-diiminoethane form after UV irradiation of 1,2-diazidoethane by N extrusion at 3 K in solid argon and can be photochemically interconverted. In a matrix isolation pyrolysis experiment at 600 °C with 1,2-diazidoethane as the starting material we observe hydrogen cyanide and formaldimine as the main decomposition products. All experimental findings are supported by deuterium labeling experiments and B3LYP/6-311++G(2d,2p) calculations. Irradiation of 1,2-diazidoethane in aqueous solution leads to the formation of imidazoles as indicated by NMR spectroscopy and GC-MS analysis. Our results underline the key role of diimines as building blocks in N-heterocyclic chemistry.
简单亚胺和二亚胺是有机合成中的常见构建块，但该化合物类别的光谱特征尚未得到很好的描述。在此，我们报告了最简单的二亚胺，即 1,2-二亚氨基乙烷的形成，以及通过低温基质隔离红外和紫外/可见光谱对其进行的光谱表征。在固态氩气中，通过 N 挤出，用 1,2-二叠氮乙烷在 3 K 下进行紫外线照射，形成了 1,2-二亚氨基乙烷的三种构象，并且可以通过光化学互变进行转化。在 600°C 的基质隔离热解实验中，以 1,2-二叠氮乙烷为起始原料，我们观察到氢氰酸和甲亚胺是主要的分解产物。所有实验结果均得到氘标记实验和 B3LYP/6-311++G(2d,2p)计算的支持。如 NMR 光谱和 GC-MS 分析所示，1,2-二叠氮乙烷在水溶液中的辐照导致咪唑的形成。我们的结果强调了二亚胺作为 N-杂环化学中构建块的关键作用。
