Deng Guohai, Dong Xuelin, Liu Qifan, Li Dingqing, Li Hongmin, Sun Qiao, Zeng Xiaoqing
College of Chemistry, Chemical Engineering and Materials Science, Soochow University, 215123 Suzhou, P. R. China.
School for Radiological and Interdisciplinary Sciences, Soochow University, 215123 Suzhou, P. R. China.
Phys Chem Chem Phys. 2017 Feb 1;19(5):3792-3799. doi: 10.1039/c6cp08125h.
The thermal-decomposition and photo-decomposition of benzenesulfonyl azide, PhS(O)N, have been studied by combining matrix-isolation IR spectroscopy and quantum chemical calculations. Upon flash vacuum pyrolysis at 800 K, the azide splits off molecular nitrogen and exclusively furnishes phenylnitrene (PhN) and SO in the gas phase. In contrast, the azide favors stepwise photodecomposition in solid Ar and Ne matrices at 2.8 K. Specifically, the UV laser photolysis (193 and 266 nm) of PhS(O)N results in the formation of the key nitrene intermediate PhS(O)N in the triplet ground state, which undergoes pseudo-Curtius rearrangement into N-sulfonyl imine PhNSO under subsequent visible light irradiation (380-450 nm). Further fragmentation of PhNSO into SO and PhN followed by ring-expansion to didehydroazepine also occurs upon visible light irradiation. The preference of the stepwise mechanism for the decomposition of PhS(O)N is supported by quantum chemical calculations using DFT B3LYP/6-311++G(3df,3pd) and CBS-QB3 methods.
通过结合基质隔离红外光谱和量子化学计算，对苯磺酰叠氮（PhS(O)N）的热分解和光分解进行了研究。在800 K下进行快速真空热解时，叠氮化物分解出分子氮，并在气相中仅生成苯基亚硝基苯（PhN）和SO。相比之下，叠氮化物在2.8 K的固态氩和氖基质中倾向于逐步光分解。具体而言，PhS(O)N的紫外激光光解（193和266 nm）导致形成处于三重态基态的关键亚硝基苯中间体PhS(O)N，在随后的可见光照射（380 - 波长450 nm）下，该中间体经历准库尔提斯重排生成N-磺酰基亚胺PhNSO。在可见光照射下，PhNSO还会进一步分解为SO和PhN，随后环扩展生成二脱氢氮杂卓。使用DFT B3LYP/6 - 311++G(3df,3pd)和CBS - QB3方法进行的量子化学计算支持了PhS(O)N分解的逐步机理偏好。
