噻吩与小分子间弱相互作用的理论研究

在B3LPY/6-311+G**水平上计算了噻吩与NH3、H2O和HF形成的复合物的结构、能量及氢键关键点处电荷密度拓扑性质。结果表明,噻吩与NH3形成两种弱C-H…N氢键;N被O取代后,除C-H…O氢键外,形成更稳定的O-H…π结构;F取代O时形成强度更大的F-H…S和F-H…π氢键,这表明典型的氢键在电负性较小的分子复合物中较为普遍;在电负性较大的分子复合物中,小分子更倾向于从噻吩平面上方接近噻吩,形成其他类型的氢键和X-H…π氢键。氢键关键点处的电荷密度拓扑性质结果表明,这些氢键强度较弱,为闭壳层相互作用。本文结论为噻吩类超分子功能材料体系的设计和合成提供一定的指导。

Theoretical study on the weak interaction between thiophene and small molecules

The structure,energy,and topological properties of electron density at the bond critical points of hydrogen bonds formed by thiophene with NH3,H2O,and HF were calculated at B3LPY/6-311+G**level.The results show that thiophene and NH3 forms two C-H…N weak hydrogen bonds.When N is replaced by O,the bond strength becomes weaker and a more stable O-H…πhydrogen bond is formed.The stronger F-H…S and F-H…πhydrogen bonds are formed when F replaces O,indicating that the typical hydrogen bonds are common in complexes with less electronegativity.While small molecules tend to approach thiophene molecules from above thiophene plane and form other types of hydrogen bonds and X-H…πhydrogen bonds when in complexes of molecules with larger electronegativity.The topological properties of electron density at the bond critical points indicate that these hydrogen bonds are weak and closed-shell interactions.The conclusions of this paper provide some guidance for the design and synthesis of supramolecular functional material systems with thiophene.