吡啶基客体分子对枝状分子表面线状模板的选择性调节

Formation of hierarchial linear monodendron templates in response to guest molecules with pyridyl terminals on graphite surfaces

利用扫描隧道显微术(STM)研究了枝状分子BIC3与4,4′-联吡啶(BP),吡啶乙炔撑衍生物(PE3,PE4)等分子在石墨表面的二元共组装结构.BIC3分子能够在端基为吡啶基的客体分子诱导下,形成柔性线状分子模板,并捕捉客体分子形成线状主客体结构.通过选择客体分子结构,可选择性调节BIC3主体模板结构及最终的主客体二元结构.例如,客体分子吡啶端基的间距决定BIC3-吡啶基分子主客体结构中的氢键作用方式,而客体分子侧向宽度及吡啶环的数目影响线状主客体结构的条垄间距和分子比例.研究结果为可控构筑线状主客体纳米结构,实现表面自组装结构的功能性提供了思路.

The two-component self-assemblies of a monodendron （BIC3） and three molecules with pyridyl terminals including 4,4＇-bipyridine （BP）,and two pyridylethynyl molecules （PE3,and PE4） were investigated by scanning tunneling microscope （STM） on graphite surface.It has been found that BIC3 can self-assemble into flexible and linear molecular templates to accommodate the pyridyl derivatives.By choosing guest molecules with different structures,BIC3 host templates and the ultimate host-guest structures can be selectively regulated.The distance of terminal pyridyl groups in the guest molecules determine the hydrogen bond pattern in the host-guest assemblies.Moreover,the size and the number of pyridyl groups of the guest molecules affect the unit cell parameter and molar ratio of different components in the resulted structures.The result is helpful for the fabrication of the linear host-guest nanostructures,and provides important insight to design two dimensional structures with desired functions.