物理化学学报Issue(2)：415-421,7.DOI:10.3866/PKU.WHXB201511191
瞬态吸收和共振拉曼光谱研究硝基对联苯氮宾、氮宾离子反应活性的影响
Investigation of the Influence of Nitro-Substitution on the Reaction of Biphenyl-Nitrene and Nitrenium Ion by Transient Absorption and Resonance Raman Spectroscopic Techniques
摘要
Abstract
Arylnitrenes and arylnitrenium ions are both short-lived intermediates that are highly reactive. In this work, nanosecond transient absorption and transient resonance Raman spectroscopic measurements were used to detect and identify the intermediates generated from the singlet 4′-nitro-4-biphenylnitrene after photolysis of the corresponding aryl azide in acetonitrile and aqueous solution. Combined with the density functional theory (DFT) simulation results, the structural and electronic characteristics of the above experimental intermediates were specified. The spectral results indicate that in aprotic solvents (such as acetonitrile), the singlet 4′-nitro-4-biphenylnitrene undergoes intersystem crossing (ISC) to the triplet nitrene. In contrast, in a protic solvent (such as the mixed aqueous solution used in this work), the singlet 4′-nitro-4-biphenylnitrene can be protonated to produce the nitrenium ion. Compared with its un-substituted counterpart, the nitro substitution has little influence on the ISC reaction pathway of the singlet 4-biphenylnitrene. With regard to the un-substituted nitrenium ion, the nitro group decreases its reactivity towards water and azide anion, while accelerating its reaction rate towards 2′-deoxyguanosine based on the different quench reaction rates between the nitrenium ion and azide anion/2′-deoxyguanosine. These results provide rich structural and kinetic information about related arylnitrenes and arylnitrenium ions, providing insights into their photolysis mechanism(s) through electronic and vibrational spectroscopic techniques.关键词
芳基叠氮/氮宾/氮宾离子/瞬态吸收/共振拉曼Key words
Aryl azide/Nitrene/Nitrenium ion/Transient absorption/Resonance Raman分类
化学化工引用本文复制引用
李亚芳,程博文,沈超,郑旭明,薛佳丹,杜勇,汤文建..瞬态吸收和共振拉曼光谱研究硝基对联苯氮宾、氮宾离子反应活性的影响[J].物理化学学报,2016,(2):415-421,7.基金项目
The project was supported by the National Natural Science Foundation of China (21202032,21205110), Science Foundation of Zhejiang Sci-Tech University, China (1206841-Y), Zhejiang Provincial Top Key Academic Discipline of Chemical Engineering and Technology, Zhejiang Sci-Tech University, China (YR2013009), and Zhejiang Provincial Natural Science Foundation, China (LY16B030008).国家自然科学基金(21202032,21205110),浙江理工大学科研启动基金(1206841-Y),浙江理工大学化学工程与技术浙江省重中之重(一级)学科开放基金(YR2013009)及浙江省自然科学基金(LY16B030008)资助项目 （21202032,21205110）
