Fragmentation of Protonated <i>N</i>-(3-Aminophenyl)Benzamide and Its Derivatives in Gas Phase
作者:Chengli Zu、Sukrit Mukhopadhyay、Patrick S. Hanley、Shijing Xia、Bruce M. Bell、David Grigg、Jeffrey R. Gilbert、John P. O’Brien
DOI:10.1007/s13361-016-1342-z
日期:2016.5.1
the formation of the rearranged ion of m/z 110. The rearrangement can be generalized to other protonated amide compounds with electron-donating groups at the meta position, such as, –OH, –CH3, –OCH3, –NH(CH3)2, –NH-Ph, and –NHCOCH3, all of which show the corresponding rearranged ions in MS/MS spectra. However, the protonated amide compounds containing electron-withdrawing groups, including –Cl, –Br, –CN
的离子米/ ž 110.06036(离子式[C 6 H ^ 8 NO] + ;误差:0.32 MDA)中的质子化的碰撞诱导解离串联质谱实验中观察到ñ - (3-氨基苯基)苯甲酰胺,其为重排据称是通过氮氧(N–O)交换产生的产物离子。N–O交换重排通过质子化N-(3-氨基苯基)-O 18-苯甲酰胺的MS / MS谱图确认,其中重排的离子[C 6 H 8 N O 18 ] +为m / z 由于存在O 18,因此有112个可用。使用密度泛函理论(DFT)在B3LYP / 6-31 g(d)水平进行的理论计算表明,包含水分子和腈离子的离子中性络合物是通过过渡态(TS - 1)形成的,随后是水分子迁移到苯胺环上,最终导致m / z 110的重排离子的形成。重排可以推广到在元位置带有供电子基团的其他质子化酰胺化合物,例如–OH,– CH 3,–OCH 3, –NH(CH 3)2 ,–NH-Ph和–NHCOCH