Protonated carbamic acid. Collisional activation and unimolecular dissociation of CH4NO + 2
作者:Helge Egsgaard、Lars Carlsen
DOI:10.1039/ft9949000941
日期:——
Protonated carbamic acid is generated by elimination of a vinyl radical from the radical cation of ethyl carbamate. Double hydrogen transfer leads to an excited state of the stable Y-configuration in addition to other isomers. The properties of gaseous CH4NO+2 have been disclosed on the basis of collisional activation mass spectrometry as well as unimolecular dissociation (MIKE) in combination with an extensive use of 15N and deuterium labelling. Thermochemical aspects of the protonated carbamic acid are discussed based on semiempirical MNDO calculations, supplementary to appearance energy measurements.
质子化氨基甲酸是通过消除氨基甲酸乙酯自由基阳离子中的乙烯基而生成的。除了其他异构体外,双氢转移还导致稳定 Y 构型的激发态。气态 CH4NO+2 的性质是在碰撞活化质谱法和单分子解离法(MIKE)的基础上,结合广泛使用 15N 和氘标记法研究出来的。质子化氨基甲酸的热化学问题是根据半经验 MNDO 计算以及外观能量测量结果进行讨论的。