The Research On Non-covalent Self-assembly Of Fluoren-based Supramolecular Organic Frameworks

With the development of organic porous materials,supramolecular organic frameworks(SOFs)materials have received more and more attention because of their characteristic advantages.But its building blocks are mostly limited to simple planar multi-armed molecules.Therefore,the expansion of the new skeletons is necessary for SOFs.Fluoren-based materials have good applications in optoelectronic fields such as organic light-emitting displays,organic light storage,organic photovoltaic cells,organic field-effect transistors,and organic lasers.Therefore,this thesis designed and synthesized a non-planar fluorenol model molecule as a building block of SOFs based on the synergistically molecular attractor-repulsor theory.Different from the conventional planar skeletons of SOFs,the introduction of the nonplanar chiral molecule of 9,9'-diphenyl-9H,9'H-[2,2'-bifluorene]-9,9'-diol(DPFOH)will provide new possibilities for the building block of SOFs.The special features of non-planar configuration and chirality make the packing mode of DPFOH is different from other planar molecules.The sterically hindered benzene rings of two chiral molecules in the crystal structure are on different sides of the planar fluorenyl group,which are connected end to end to form a single pore.Therefore,its channels are independent and do not share molecules with each other,moreover,they even stagger from each other to form new pores.Additionally,the characteristics of chiral molecule of DPFOH make a special three-dimensional fishbone accumulation in the axial direction of the channels.The discovery of the successful accumulation of this chiral molecule to obtain SOFs crystals will expand the design program of SOFs materials and become a new way of thinking during the preparation of SOFs materialsOrganic micro/nano crystal materials are formed through the process of self-assembly Therefore,organic micro/nano crystal materials have many characteristic advantages.This thesis found that supramolecular organic frameworks(SOFs)are different from covalent organic frameworks(COFs)and metal-organic frameworks(MOFs).They connect through unique non-covalent bonds,which are a good kind of materials used for regulation of micro/nano crystals morphology.But up to now,few researchers have tried to utilize SOFs to prepare micro/nano crystals.In this paper,they synthesized 9,9'-diphenyl-9H,9'H-[2,2'-bifluorene]-9,9'-diol and prepared SOF materials.Later,we used this material to fabricate the structure of microtubes by simple reprecipitation method.After that,the author found that the one-dimensional channels in SOFs materials may promote the formation of tubular structures,then the rule was further verified through theoretical calculations.This finding will help to simplified and controlled prepare micro/nano-scale tubular structure crystals.Finally,we studied the noncovalent bond self-assembly behavior of chiral fluorenyl grid molecules as intrinsic pore SOFs and further explored the crystal packing behavior of chiral fluorenyl molecules.