National High Magnetic Field Laboratory, Tallahassee, FL 32310, USA.
J Am Soc Mass Spectrom. 2013 Feb;24(2):213-21. doi: 10.1007/s13361-012-0512-x. Epub 2013 Jan 8.
We report the first charge reversal experiments performed by tandem-in-time rather than tandem-in-space MS/MS. Precursor odd-electron anions from fullerene C(60), and even-electron ions from 2,7-di-tert-butylfluorene-9-carboxylic acid and 3,3'-bicarbazole were converted into positive product ions ((-)CR(+)) inside the magnet of a Fourier transform ion cyclotron resonance mass spectrometer. Charge reversal was activated by irradiating precursor ions with high energy electrons or UV photons: the first reported use of those activation methods for charge reversal. We suggest that high energy electrons achieve charge reversal in one step as double electron transfer, whereas UV-activated (-)CR(+) takes place stepwise through two single electron transfers and formally corresponds to a neutralization-reionization ((-)NR(+)) experiment.
我们报告了首次通过串联时间而不是串联空间的 MS/MS 进行的电荷反转实验。富勒烯 C(60)的前体奇数电子阴离子，以及 2,7-二叔丁基芴-9-羧酸和 3,3'-联咔唑的偶数电子离子，在傅里叶变换离子回旋共振质谱仪的磁铁内转化为正产物离子 ((-)CR(+))。电荷反转是通过用高能电子或紫外线光子辐照前体离子来激活的：这是首次报道使用这些激活方法进行电荷反转。我们认为，高能电子通过两步双电子转移一步实现电荷反转，而 UV 激活的 (-)CR(+)则通过两个单电子转移逐步发生，形式上对应于中和再电离 ((-)NR(+))实验。
