Carbazolyl Nitrenium Ion: Electron Configuration and Antiaromaticity Assessed by Laser Flash Photolysis, Trapping Rate Constants, Product Analysis, and Computational Studies
作者:Arthur H. Winter、Harry H. Gibson、Daniel E. Falvey
DOI:10.1021/jo0708184
日期:2007.10.1
comparable to structurally similar closed-shell diarylnitrenium ions, but spectroscopic evidence favors an open-shell singlet diradical assignment for the observed nitrenium ion. The carbazolyl nitrenium ion is also more reactive than diarylnitrenium ions as a likely result of antiaromatic character. Ab initio and hybrid DFT calculations were performed to address the degree of antiaromaticity in this and
1-(咔唑-9-基)-2,4,6-三甲基吡啶四氟硼酸酯的激光闪光光解产生咔唑基亚硝酸根离子(τ= 333 ns,k obs = 3.0×10 6 M -1 s -1)在CH 3 CN中的570和620 nm处 发现该亚硝酸根离子具有与结构相似的闭壳二芳基硝酸根离子相当的反应性,但是光谱证据支持观察到的亚硝酸根离子的开壳单重双自由基分配。由于抗芳族特性,咔唑基氮离子也比二芳基硝酸根离子更具反应性。从头算 通过优化几何结构,独立于原子核的化学位移和等渗反应的分析,进行了混合DFT计算,以解决该和类似的氮离子中的抗芳香性程度。