摘要:
利用从头算Hartree-Fock方法和密度泛函理论方法,研究了1,3,5-苯三酸(苯三酸,TMA)和1,3,5-苯三酚(间苯三酚,THB)在高定向热解石墨(HOPG)上的增长过程.计算结果表明,两种分子的不同组装行为起源于氢键作用下的成核过程.TMA能够形成头碰头和非头碰头结构,从而形成两种不同的孔洞结构;THB只能形成非头碰头结构,从而形成密堆积结构.这些计算揭示了这两种结构相似的分子形成不同扫描隧道显微图像的微观机理.
Abstract:
The ab initio Hartree Fock method and density functional theory (DFT) are employed to investigate the growth process of 1, 3, 5-benzenetricarboxylic acid (trimesic acid, TMA) and 1, 3, 5-trihydroxybenzene (phloroglucinol, THB) on highly oriented pyrolytic graphite (HOPG). The calculated results demonstrate that the different assembling behaviors of the two molecules result from their nucleation process driven by the hydrogen bonding.TMA can form both head-to-head and non-head-to head structures and thus form two kinds of hole structures, while THB is ready to form non-head-to-head structure and results in the formation of a closed packed structure. These calculations disclose the microscopic mechanism of the different scanning tunneling microscopy (STM) images of these two structurally similar molecules.
下载: