通过近红外激光诱导构象变化、二维相关分析和量子力学非谐计算辅助的基质隔离红外光谱法鉴定丝氨酸构象异构体
Identification of Serine Conformers by Matrix-Isolation IR Spectroscopy Aided by Near-Infrared Laser-Induced Conformational Change, 2D Correlation Analysis, and Quantum Mechanical Anharmonic Computations.
作者信息
Najbauer Eszter E, Bazsó Gábor, Apóstolo Rui, Fausto Rui, Biczysko Malgorzata, Barone Vincenzo, Tarczay György
机构信息
†Laboratory of Molecular Spectroscopy, Institute of Chemistry, Eötvös University, PO Box 32, H-1518, Budapest 112, Hungary.
‡Department of Chemistry, University of Coimbra, 3004-535 Coimbra, Portugal.
出版信息
J Phys Chem B. 2015 Aug 20;119(33):10496-510. doi: 10.1021/acs.jpcb.5b05768. Epub 2015 Aug 5.
The conformers of α-serine were investigated by matrix-isolation IR spectroscopy combined with NIR laser irradiation. This method, aided by 2D correlation analysis, enabled unambiguously grouping the spectral lines to individual conformers. On the basis of comparison of at least nine experimentally observed vibrational transitions of each conformer with empirically scaled (SQM) and anharmonic (GVPT2) computed IR spectra, six conformers were identified. In addition, the presence of at least one more conformer in Ar matrix was proved, and a short-lived conformer with a half-life of (3.7 ± 0.5) × 10(3) s in N2 matrix was generated by NIR irradiation. The analysis of the NIR laser-induced conversions revealed that the excitation of the stretching overtone of both the side chain and the carboxylic OH groups can effectively promote conformational changes, but remarkably different paths were observed for the two kinds of excitations.
通过基质隔离红外光谱结合近红外激光辐照研究了α-丝氨酸的构象异构体。该方法在二维相关分析的辅助下，能够明确地将光谱线归为各个构象异构体。基于将每个构象异构体至少九个实验观测到的振动跃迁与经验标度（SQM）和非谐（GVPT2）计算的红外光谱进行比较，确定了六个构象异构体。此外，证明了在氩基质中至少还存在一种构象异构体，并且通过近红外辐照在氮基质中产生了半衰期为(3.7 ± 0.5) × 10(3) s的短寿命构象异构体。对近红外激光诱导的转变的分析表明，侧链和羧基OH基团的伸缩倍频的激发都能有效地促进构象变化，但两种激发观察到的路径明显不同。
Zotero 插件