利用平面σ-芳香性增强电子输运能力  

Utilizing Planarσ-Aromaticity to Enhance Electron Transport Abilities

作　　者：王治业 肖博怀 Wang Zhiye;Xiao Bohuai(The State Key Laboratory of Refractories and Metallurgy,the Institute of Advanced Materials and Nanotechnology,Faculty of Materials,Wuhan University of Science and Technology,Wuhan 430081)

机构地区：[1]武汉科技大学耐火材料与冶金国家重点实验室先进材料和纳米技术研究院材料学部,武汉430081

出　　处：《化学学报》2024年第5期520-526,共7页Acta Chimica Sinica

基　　金：湖北省自然科学基金(No.2022CFC007)资助。

摘　　要：芳香性是有机化学中的重要概念,传统芳香族化合物的芳香性通常源于π电子在环上下平面产生的高度离域,而σ-芳香性则主要源于分子内σ键和轨道重叠,两者均能影响分子的电子传输能力.采用密度泛函理论结合非平衡格林函数(DFT+NEGF)方法对苯、噻吩和呋喃及其衍生物进行了芳香性和电子输运性质的系统研究.计算结果表明,苯、噻吩和呋喃分子的电子输运性质受π-芳香性和σ-芳香性影响,其中σ-芳香性和电子传输正相关,而π-芳香性和电子传输能力成负相关.含有两个芳香环的联苯二巯基(DB)、联噻吩二巯基(DT)和联呋喃二巯基(DF)分子的电子传输能力受分子平面化影响较大,DF中呋喃环表现出比DT中噻吩环更大的NICS(1)zz值.芳香性化合物具有更好的共平面趋势,通过F原子修饰DT和DF分子产生分子内F…S和F…O非共价相互作用的设计策略可以极大增加分子平面性和刚性.同时,含有分子内F…S和F…O相互作用的虚拟五元环具有平面σ-芳香性特征,有效促进电子沿F…S和F…O路径进行传输,从而提高电子传输能力.本研究有助于进一步理解分子芳香性与电子传输能力之间的内在关系,为未来设计更高效的电子器件提供策略.In organic chemistry,aromaticity is a fundamental concept.The aromaticity of traditional aromatic compounds usually comes from the high delocalization ofπ-electrons on the upper and lower planes of the ring,whileσ-aromaticity mainly comes from the intramolecularσbond and orbital overlap,both of which can affect the electron transport capacity of the molecule.In this study,density functional theory combined with non-equilibrium Green's function(DFT+NEGF)meth-od are used to systematically investigate the aromaticity and electronic transport properties of benzene,thiophene,furan,and their derivatives.The computational results reveal that bothπ-aromaticity andσ-aromaticity have pronounced effects on mo-lecular electronic transport,whereσ-aromaticity shows a positive correlation with electron transmission,whereasπ-aromaticity displays a negative correlation.The charge transfer properties of diphenyl dithiol(DB),dithiophene dithiol(DT)and difuran dithiol(DF)molecules containing two aromatic rings are significantly influenced by molecular planariza-tion.Moreover,the furan ring in DF exhibits a larger NICS(1)zz value than the thiophene ring in DT.Furthermore,aromatic compounds typically exhibit a better coplanar trend.The molecular design strategy involving the modification of DT and DF molecules with F atom generates intramolecular F…S and F…O non-covalent interactions,which significantly enhance mo-lecular planarity and rigidity.Meanwhile,the virtual five-membered ring structures containing intramolecular F…S and F…O interactions haveσ-aromaticity characteristics,effectively promoting electron transport along F…S and F…O pathways,thereby improving the electron transport capacity.This research contributes to further understanding of the intrinsic relation-ship between molecular aromaticity and electronic transport capacity,and provides strategies for designing more efficient electronic devices in the future.

关 键 词：芳香性 电子传输 平面性 分子内相互作用 密度泛函理论结合非平衡格林函数 

分 类 号：O641.1[理学—物理化学]