A series of isomeric triaryl compounds with a modular positioning of the halogen and NO2 groups have been synthesized by the azideâalkyne âclick reactionâ and have been characterized by single crystal X-ray structure analysis. This isomeric series has provided an opportunity for understanding the efficiency of the bifurcated halogenâ¯NO2 synthon in the organization of the molecules in the crystalline lattice. The changes in molecular conformation, crystal packing and supramolecular aggregation due to the change in the relative positioning of the complementary groups, halogen atom and the NO2 group on ring A and ring C respectively, have been discussed. All the isomers synthesized are crystalline and establish the triazole as a reliable linker for crystal engineering oriented molecular synthesis. The 2-NO2 derivatives display in general, a helical architecture and 3-NO2 derivatives exhibit a centrosymmetric dimeric assembly via the complementary CâHâ¯O interactions leading to either a helical or a 2-dimensional sheet pattern. The molecular organization in 4-NO2 derivatives revealed in general a 2D sheet pattern.
通过
叠氮â炔的“点击反应”,合成了一系列异构的三芳基化合物,卤素和
NO2基团的位置模块化,并通过单晶X射线结构分析进行表征。该异构系列为理解分叉卤素⯠合成单元在分子在晶体格子的组织效率提供了机会。由于互补基团的相对位置变化,即卤素原子和 基团分别在A环和C环上的变化,导致的分子构象、晶体堆积和超分子聚集的变化进行了讨论。所有合成的异构体均为结晶,确立了三嗪类化合物作为晶体工程导向分子合成的可靠连接体。一般而言,2- 衍
生物展现出螺旋结构,而3- 衍
生物则通过互补的C–Hâ¯O相互作用表现出中心对称的二聚组装,形成螺旋或二维片状模式。4- 衍
生物的分子组织整体上揭示出二维片状模式。