非对映体
化学
构象异构
质子化
红外多光子离解
电喷雾电离
结晶学
离解(化学)
立体化学
谱线
手性(物理)
电离
分子
质谱法
物理化学
离子
物理
有机化学
量子力学
手征对称破缺
色谱法
Nambu–Jona Lasinio模型
夸克
天文
作者
Antonello Filippi,Caterina Fraschetti,Laura Guarcini,Costantino Zazza,Tadashi Ema,Maurizio Speranza
出处
期刊:ChemPhysChem
[Wiley]
日期:2017-08-07
卷期号:18 (18): 2475-2481
被引量:7
标识
DOI:10.1002/cphc.201700732
摘要
Abstract The infrared multiphoton dissociation (IRMPD) spectra of electrospray ionization (ESI)‐formed proton‐bound complexes between the axially chiral multifunctional macrocycle M aR and d ‐ and l ‐phenylalanine ( P D and P L ) or d ‐ and l ‐3,4‐dihydroxyphenylalanine ( D D and D L ) are recorded in the =2800–3700 cm −1 region. Whereas the diastereomeric [ M aR ⋅ H ⋅P D ] + and [ M aR ⋅ H ⋅P L ] + complexes do not show any significant spectral differences, the spectrum of [ M aR ⋅ H ⋅D D ] + clearly diverges from that of its [ M aR ⋅ H ⋅D L ] + diastereomer. A comparison of the experimental spectra with the B3LYP/6‐31G**‐calculated harmonic vibrational frequencies of a number of stable structures indicates the formation, in the ESI source, of very similar spectroscopically active structures, with the protonated amino acid placed outside the flat cavity of the macrocycle and hydrogen‐bonded at its O 2 center. Different spectral signatures of the [ M aR ⋅ H ⋅D D ] + and [ M aR ⋅ H ⋅D L ] + complexes are attributed to the coexistence of several stable rotamers in the ESI source.
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