摘要
利用扫描隧道显微镜研究了荧光液晶分子2,5-二-[2-(3,4-二-十二烷氧基-苯基)-乙烯基]-3,6-二甲基吡嗪(BPDP12)在石墨表面上自组装单层膜的结构.实验结果表明,该化合物在石墨表面形成两种自组装结构:一种是稳定的,分子的共轭中心相互平行,烷基链相互交错的密排结构;另一种是不稳定的,分子的共轭中心彼此为烷基链所分隔的非密排结构.分子之间较强的π-π作用和分子烷基链之间的范德华作用力对分子组装的取向形成竞争,是产生两种不同组装结构的根本原因.
The nanostructure studies have been performed to the fluorescent and liquid-crystal molecule （2, 5- bis-[2-（3,4-bis-dodecyloxy-phenyl）-vinyl]-3,6-dimethyl-pyrazine（BPDP12）） on highly oriented pyrolytic graphite （HOPG） using scanning tunneling microscopy （STM）. The well-organized 2-D monolayer images reveal two kinds of configurations. The structure （Ⅰ） is a stable and closely packed arrangement, in which all the conjugated cores are parallel to each other and the alkyl chains of the molecules interdigitate over the full length; while the structure （Ⅱ） is an unstable and unclosely packed arrangement, in which all the conjugated cores are separated by the alkyl chains. The formation of above two structures owes to the competition between the stronger intermolecular π-π interactions and the van der Waals forces of alkyl chains during the self-assembly.
出处
《物理化学学报》
SCIE
CAS
CSCD
北大核心
2005年第8期925-928,共4页
Acta Physico-Chimica Sinica
基金
国家自然科学基金(20025308
20103008)
国家基础研究重大项目计划(G2000077501)资助~~
关键词
扫描隧道显微镜
自组装
吡嗪衍生物
Scanning tunneling microscopy （STM）, Self-assembly, Pyrazine derivative
