Two-dimensional self-assemblies of four partially fluorinated molecules, 1,4-bis（2,6-difluoropyridin-4-yl）benzene, 4,4＇-bis（2,6-difluoropyridin-4-yl）-1,1＇-biphenyl, 4,4＇-bis（2,6-difluoropyridin-4-yl）-1,1＇：4＇,1＇-terphenyl and 4,4＇-bis（2,6-difluoropyridin-3-yl）-1,1＇-biphenyl, involving weak intermolecular C-H···F and C-H···N hydrogen bonds were systematically investigated on Au（111） with low-temperature scanning tunneling microscopy. The inter-molecular connecting modes and binding sites were closely related to the backbones of the building blocks, i.e., the molecule length determines its binding sites with neighboring molecules in the assemblies while the attaching positions of the N and F atoms dictate its approaching and docking angles. The experimental results demonstrate that multiple weak hydrogen bonds such as C-H···F and C-H···N can be efficiently applied to tune the molecular orientations and the self-assembly structures accordingly.
Xin JinJacob R. CramerQi-Wei ChenHai-Lin LiangJian ShangXiang ShaoWei ChenGuo-Qin XuKurt V. GothelfKai Wu
为建立呼肠孤病毒(RV)的三维模型,本研究利用冷冻电镜(cryo-EM)单颗粒三维重构技术获得了分辨率为10.6A的果子狸RV M PC/04株的三维结构。三维重构结果显示,果子狸RV M PC/04株具有哺乳动物RV典型的形态。该病毒由内外两层衣壳蛋白组成,呈二十面体对称结构。内衣壳的外面包裹着一层由200个μ13σ33异源六聚体复合物构成的外衣壳,三角形剖分函数T=13。同时我们还观察到了该病毒主要蛋白之间的连接方式。本研究探讨为不同宿主的RV的形态和结构比较研究提供了相关的数据。
