Tian Ge, Li Huifang, Ma Wanyong, Wang Yixuan
School of Chemistry and Pharmaceutical Engineering, Qilu University of Technology, Jinan, Shandong 250353, China ; Department of Natural Science, Albany State University, Albany, GA 31705, USA.
Department of Natural Science, Albany State University, Albany, GA 31705, USA ; Department of Chemistry, Gannan Normal University, GanZhou, JiangXi 341000, China.
Comput Theor Chem. 2015 Jun 15;1062:44-49. doi: 10.1016/j.comptc.2015.03.023.
Adsorptions of histidine on the functionalized (10,0) single-walled carbon nanotube (SWNT) and graphene were investigated using density function theory methods, M05-2x and DFT-D. The results show that the binding of the histidine ring to the functionalized SWNT is weaker than that to the pristine SWNT for both singlet and triplet complexes, regardless of the electron-donating (-OH, -NH) or electron-withdrawing (-COOH) character and their attached sites. The present decreased binding is opposite to the well-known enhanced binding in the substituted benzene dimers. Since the atoms of the histidine are distant from the substituent atoms by over 6Å, there would be no interaction between histidine and the substituent as in the case of the substituted benzene systems. The decreased binding can be mainly driven by the aromaticity of the functionalized SWNT. The nucleus-independent chemical shift (NICS) index analysis for the functionalized SWNTs in deed shows that local aromaticity of SWNT is decreased because of the electron redistribution induced by functional groups, and the stacking between the histidine ring and -SWNT is therefore decreased as compared to the pristine SWNT. However, the above trend does not remain for the binding between the histidine and graphene. The binding of the histidine to the functionalized graphene with -OH and -NH is just slightly weaker than that to the pristine graphene, while its binding to COOH-SWNT becomes a little bit stronger.
采用密度泛函理论方法M05 - 2x和DFT - D研究了组氨酸在功能化(10,0)单壁碳纳米管(SWNT)和石墨烯上的吸附情况。结果表明，对于单重态和三重态配合物，无论供电子(-OH、-NH)或吸电子(-COOH)特性及其附着位点如何，组氨酸环与功能化SWNT的结合都比与原始SWNT的结合弱。目前这种结合力的降低与取代苯二聚体中众所周知的增强结合力相反。由于组氨酸的原子与取代原子的距离超过6Å，与取代苯体系的情况一样，组氨酸与取代基之间不存在相互作用。结合力的降低主要是由功能化SWNT的芳香性驱动的。对功能化SWNTs的核独立化学位移(NICS)指数分析确实表明，由于官能团引起的电子重新分布，SWNT的局部芳香性降低，因此与原始SWNT相比，组氨酸环与-SWNT之间的堆积减少。然而，组氨酸与石墨烯之间的结合不存在上述趋势。组氨酸与带有-OH和-NH的功能化石墨烯的结合仅比与原始石墨烯的结合略弱，而其与COOH - SWNT的结合则变强了一点。
