Sterling Chemistry Laboratory, Yale University, New Haven, Connecticut 06520, United States.
Anal Chem. 2013 Aug 6;85(15):7339-44. doi: 10.1021/ac401228y. Epub 2013 Jul 10.
Cryogenic ion vibrational predissociation (CIVP) spectroscopy is used to structurally characterize electrochemically (EC)-generated oxidation products of the benchmark compound reserpine. Ionic products were isolated using EC-electrospray ionization (ESI) coupled to a 25 K ion trap prior to injection into a double-focusing, tandem time-of-flight photofragmentation mass spectrometer. Vibrational predissociation spectroscopy was carried out by photoevaporation of weakly bound N2 adducts over the range 800-3800 cm(-1) in a linear (i.e., single photon) action regime, thus enabling direct comparison of the experimental vibrational pattern with harmonic calculations. The locations of the NH and OH stretching fundamentals are most consistent with formation of 9-hydroxyreserpine, which is a different isomer than considered previously. This approach thus provides a powerful structural dimension for the analysis of electrochemical processes detected with the sensitivity of mass spectrometry.
低温离子振动预解离 (CIVP) 光谱学用于结构表征电化学 (EC) 生成的基准化合物利血平的氧化产物。离子产物通过 EC-电喷雾电离 (ESI) 与 25 K 离子阱耦合，在注入双聚焦串联飞行时间光解碎片质谱仪之前进行分离。通过在 800-3800 cm(-1) 的线性（即单光子）作用范围内光蒸发弱结合的 N2 加合物进行振动预解离光谱学，从而可以直接将实验振动模式与谐波计算进行比较。NH 和 OH 伸缩基频的位置与 9-羟基利血平的形成最为一致，这是一种与以前考虑的不同的异构体。因此，这种方法为电化学过程的分析提供了一个强大的结构维度，其检测灵敏度可与质谱法相媲美。
