Paragi Gábor, Fonseca Guerra Célia
Department of Theoretical Chemistry and Amsterdam Center for Multiscale Modeling, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV, Amsterdam, The Netherlands.
MTA-SZTE, Supramolecular and Nanostructured Materials Research Group, Dóm tér 8, Szeged, Hungary.
Chemistry. 2017 Mar 2;23(13):3042-3050. doi: 10.1002/chem.201604830. Epub 2017 Jan 16.
The guanine nucleobase can self-assemble into tetrameric or ribbon structures on surfaces or in solution. The origin for the occurrence of different aggregation patterns has not yet been investigated. Herein, a quantum chemical study on the different self-assembled structures of guanine and xanthine by using dispersion-corrected DFT is presented. Theoretical investigations can be used to explain, from an electronic point of view, the differences between the experimental findings. With quantitative Kohn-Sham molecular orbital theory and the accompanying energy decomposition analysis, the hydrogen-bonding mechanism within the guanine ribbons can be disclosed and the preferred self-assembled structures under different experimental conditions can be explained. An important role of the σ-electronic system in the guanine self-assembled structures is revealed as the main factor for the switch between different arrangements on surfaces and in crystals.
鸟嘌呤核碱基可在表面或溶液中自组装成四聚体或带状结构。不同聚集模式出现的原因尚未得到研究。本文介绍了一项通过使用色散校正密度泛函理论（DFT）对鸟嘌呤和黄嘌呤不同自组装结构进行的量子化学研究。理论研究可从电子角度解释实验结果之间的差异。借助定量的科恩-沈分子轨道理论及伴随的能量分解分析，可揭示鸟嘌呤带内的氢键机制，并解释不同实验条件下的优选自组装结构。σ电子系统在鸟嘌呤自组装结构中的重要作用被揭示为表面和晶体中不同排列之间转换的主要因素。
