Correcting the record: the dimers and trimers of trans-N-methylacetamide
Correcting the record: the dimers and trimers of trans-N-methylacetamide
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DOI：
10.1039/c6cp07989j
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发表时间：
2017-05-07
影响因子：
3.3
通讯作者：
Suhm, Martin A.
中科院分区：
文献类型：
--
作者：
Forsting, Thomas;Gottschalk, Hannes C.;Suhm, Martin A.
反式-N-甲基乙酰胺二聚体可作为肽中氢键的简单模型，没有任何主链扭曲。它的首选结构代表了蛋白质相互作用的准确量子化学描述的基准系统。三聚体允许两个线性或三个应变氢键，前者是迄今为止文献中考虑的唯一结构基序，但后者由于伦敦分散而在能源方面大幅获胜。线性拉曼和红外超音速喷射技术与 B3LYP-D3/aug-cc-pVTZ 量子化学预测的结合纠正了基于混合密度泛函而无需色散校正的早期尝试性光谱分配。将喷射冷却单体的线性酰胺 I-III 红外光谱与最近通过作用光谱获得的光谱进行比较。
The dimer of trans-N-methylacetamide serves as a simple model for hydrogen bonds in peptides, free of any backbone distortions. Its preferred structures represent benchmark systems for an accurate quantum chemical description of protein interactions. The trimer allows for either two linear or three strained hydrogen bonds, with the former being the only structural motif considered so far in the literature, but the latter winning in energy by a large margin due to London dispersion. A combination of linear Raman and infrared supersonic jet techniques with B3LYP-D3/aug-cc-pVTZ quantum chemical predictions corrects earlier tentative spectroscopic assignments based on a hybrid density functional without dispersion correction. Linear Amide I-III infrared spectra of the jet-cooled monomer are compared to those recently obtained by action spectroscopy.