Key Laboratory of Chemical Biology and Organic Chemistry of Henan Province, Department of Chemistry, Zhengzhou University, Zhengzhou 450052, China.
J Mass Spectrom. 2011 Apr;46(4):352-8. doi: 10.1002/jms.1900.
Fragmentation pathways of a series of pentacoordinated bisaminoacylspirophosphoranes were elucidated by electrospray ionization multistage mass spectrometry (ESI-MS(n)) in negative mode. The deprotonated ions of pentacoordinated bisaminoacylspirophosphoranes tend to eliminate a corresponding amino acid to form base peak. The hydrogen/deuterium exchange experiment, the high-resolution mass spectrometry, (13)C stable isotope labeling experiment and theoretical calculations were used to rationalize the proposed fragmentation pathways and to verify the differences between the fragmentation pathways. The results indicate that the negative molecular ions of pentacoordinated bisaminoacylspirophosphoranes dissociate through its open-chain tricoordinated tautomers. The relative Gibbs free energies (ΔG) of the product ions and proposed fragmentation pathways were estimated using the B3LYP/6-31 + + G(d, p) model. The results have some potential applications in the identification structures of similar spirophosphorane compounds by ESI-MS(n).
通过电喷雾电离多级质谱（ESI-MS(n)）在负离子模式下，阐明了一系列五配位双氨基酰基螺膦烷的断裂途径。五配位双氨基酰基螺膦烷的去质子离子倾向于消除相应的氨基酸，以形成基峰。通过氢/氘交换实验、高分辨质谱、（13）C 稳定同位素标记实验和理论计算，对提出的断裂途径进行了合理化，并验证了断裂途径之间的差异。结果表明，五配位双氨基酰基螺膦烷的负离子通过其开链三配位互变异构体解离。使用 B3LYP/6-31 + + G(d, p)模型估算了产物离子和建议的断裂途径的相对吉布斯自由能（ΔG）。这些结果在通过 ESI-MS(n)鉴定类似螺膦烷化合物的结构方面具有一定的应用潜力。
