Dynamic Self-assembly Of Molecular Cages Based On Semi-rigid Ligands

The question of how far one could push chemical self-assembly was identified in 2005 as one of the top 25 scientific challenges for the next 25 years.Coordination-driven self-assembly based on metal species and organic ligands has been proved to be a very useful method in the construction of well-defined supramolecular architectures with specific topology and functionality.From a mechanistic standpoint,coordination-driven self-assembly process can be broken into two general categories:those under thermodynamic control and those under kinetic control.Most coordination-driven self-assembly systems are thermodynamic-control,only a few dynamic assembly systems which contain metastable kinetic intermediates and stable thermodynamic products have been developed.How to use external stimulus to selectively improve or inhibit their assembly routes in a dynamic assembly system has been highly challenging.This dissertation focuses on dynamic self-assembling of molecular cage,which contains three chapters.Chapter ? is an introduction part,in which a brief introduction of coordination chemistry is presented.The development of metal-organic coordination metallocages,including prepation,application,dynamic assembly,is also described.In chapter ?,a temperature and anions induced self-assembly system based on dynamic metallocage is frstly presented,which induced by SbF6-anions,both of kinetic product and thermodynamic product can be assembled simultaneously at 30 ? based on Ag6L4(SbF6)6 metallocage.Raising temperature up to 40 ? results to selective inhibition of their kinetic product;driven by BF4-anions,dynamic Ag6L4(BF4)6 metallocages prior to self-assemble into thermodynamic-control polycage at 25 ?,lowing temperature down to 0 ? leads to selective inhibition of their thermodynamic product.Moreover,another dyanmic assembly system based on Hg3L'2,Hg4L'4,Hg6L'8 metallocages is also demonstrated,in which such metallocage can be converted reversibly.In chapter ?,both of summary and outlook on coordination metallocage are presented.