Attempted cocrystallisation of brominated and iodinated octafluoroazobenzene derivatives with morpholine led to the exhaustive replacement of fluorine substituents that are in ortho-positions to the azobenzene with sterically demanding morpholine groups. The resulting molecules exhibit a highly unusual strained conformation of the azobenzene unit, in which the terminal phenyl rings adopt a mutually nearly completely orthogonal orientation. Substitution of ortho-fluorine groups with N-morpholine fragments provides molecules with active halogen bond donor and acceptor sites that guide the molecular self-assembly in the solid state towards the formation of polymeric halogen-bonded chains.
溴化和
碘化八
氟偶氮苯衍
生物与吗啉的共结晶尝试导致了对
偶氮苯邻位
氟取代基的彻底取代,这些取代基被空间要求高的吗啉基团取代。所得分子表现出
偶氮苯单元非常不寻常的紧张构象,其中末端苯环采用几乎完全正交的取向。用N-吗啉片段取代邻位
氟基团为分子提供了活性卤键供体和受体位点,引导固态分子自组装形成聚合卤键链。