IRMPD spectroscopy shows that AGG forms an oxazolone b2+ ion.
IRMPD spectroscopy shows that AGG forms an oxazolone b2+ ion.
复制标题
IRMPD 光谱显示 AGG 形成恶唑酮 b2 离子。
DOI：
10.1021/ja8067929
复制
发表时间：
2008
影响因子：
15
通讯作者：
Wysocki,VickiH
中科院分区：
文献类型：
--
作者：
Yoon,SungHwan;Chamot-Rooke,Julia;Perkins,BrittanyR;Hilderbrand,AmyE;Poutsma,JohnC;Wysocki,VickiH
红外多光子解离（IRMPD）光谱结合理论振动光谱提供了一个强有力的工具，探测结构。该技术已被用于探测质子化的环状AG和AGG的b2+离子的结构。质子化cyclo AG的实验光谱与二酮哌嗪的理论光谱非常吻合。该光谱最好地对应于丙氨酸和甘氨酸酰胺氧处质子化的两种结构的组合。质子化AGG的b2+离子的实验光谱与环氮上质子化的恶唑酮结构的理论光谱最匹配。特别是，与质子化cAG的实验光谱相比，1970 cm − 1处的羰基伸缩带蓝移了200 cm− 1，表明这两种结构是不同的。这是第一次获得了b2+离子的IRPD光谱，并且对于该离子，根据先前的计算和实验提出的恶唑酮结构通过光谱方法得到了证实。
Infrared multiple photon dissociation (IRMPD) spectroscopy combined with theoretical vibrational spectra provides a powerful tool for probing structure. This technique has been used to probe the structure of protonated cyclic AG and the b2+ion from AGG. The experimental spectrum for protonated cyclo AG compares very well with the theoretical spectra for a diketopiperazine. The spectrum corresponds best to a combination of two structures protonation at the alanine and glycine amide oxygens. The experimental spectrum for the b2+ion from protonated AGG matches best to the theoretical spectrum for an oxazolone structure protonated on the ring nitrogen. In particular, the carbonyl stretching band at 1970 cm−1is blue-shifted by ∼200 cm−1compared to the experimental spectrum for protonated cAG, indicating that these two structures are distinct. This is the first time that an IRPD spectrum of a b2+ion has been obtained and, for this ion, the oxazolone structure proposed based on prior calculations and experiments is confirmed by the spectroscopic method.