Design And Synthesis Of Some New Macrocyclic Arenes And Their Stimuli-responsive Self-assembly

In the past decades,scientists showed great interests in supramolecular chemistry.In this area,the design and synthesis of macrocyclic hosts with special topologies and unique host-guest properties are always of great challenges.Chemists have already constructed varieties of host molecules through organic synthesis,reversible covalent bond self-assembly,coordination-driven self-assembly and etc.,which have been widely applied in the field of materials,biology and medicine due to their different recognition properties.In the past 5 years,our group focused on the design and synthesis of macrocyclic hosts.In 2015,we firstly reported a new kind of macrocycles:4,4'-biphen[n]arenes,which constructed by biphenyl monomers.We also explored the modifications of biphen[n]arenes,and investaged their host-guest properties recently.Then,in 2017 and 2019,we reported the synthesis of2,2'-biphen[n]arenes and terphen[n]arenes/quaterphen[n]arenes respectively,developing a new research fields of(expanded)biphen[n]arenes' supramolecular host family.Based on the results metioned above,we do the following researches in this project:(1).We design and synthesize 2,2',4,4'-biphen[n]arene(n = 3 & 5)macrocycles.And we investigate the stimuli-responsive conformational exchanges between two preexisting conformations of 2,2',4,4'-tetramethoxyl biphen[3]arene(Me BP3),which can be realized by solvent effect,temperature variation,guest binding and acid/base addition.(2).We employ the synthesized method of biphen[n]arenes in the construction of molecular cages,and investigate the host-guest properties of carboxylated cage in water.(3).We construct metallacage/bis-metallacage through Pt(II)heteroligation of the double-bridged tweezer bearing pyridyl moieties and the carboxylated ligands.Then we investigate the controllable stimuli-responsive catenation of this metallacage/bis-metallacage in solid state and in solution.In this project,we construct some new macrocyclic arenes and molecular cages,as well as metallacage/bis-metallacage with endo hydrogen bond binding sites.Besides,we explore the host-guest properties and stimuli-responsive self-assembly of these molecules.We think these works may provide an insight of design and synthesis of new molecular hosts and the controllable stimuli-responsive self-assembly.