Construction And Applications Of Indolocarbazole-based Covalent Organic Frameworks

Covalent organic frameworks(COFs)are a new class of crystalline organic porous materials linked by covalent bonds.Most studies in this field have currently focused on two-dimensional/ three-dimensional new topologies or based on different functionalized applications.Indolecarbazole(ICZ)is a very important heterocyclic structure,is also a functional unit.Furthermore,ICZ can be easily synthesized and functionalized for a wide range of applications in the field of optoelectronics.Accordingly,in this thesis,we are focused on the construction of the ICZ-based COFs and its application in fluorescence recognition.In Chapter 1,we briefly reviewed the design and application of covalent organic framework materials,and then introduced the basic properties of ICZ and its applications in optoelectronics.In Chapter 3,five nevol COFs were synthesized using three different linear ICZ precursors and different aldehydes.They were named LZU-170,LZU-171,LZU-172,LZU-173 and LZU-174,respectively.The relationship between the precursor structure and the fluorescence properties of the materials was studied.It was found that changing the type of precursor had a large effect on the fluorescence of the material,while the fine modification of a precursor could play a fine role in the fluorescence of the material.In Chapter 4,we tested the fluorescence recognition effect of some materials and found that in the solid fluorescence recognition,the aromatic compound with the electron withdrawing group had a quenching effect on the fluorescence of the material.For example,nitrobenzene can calm the fluorescence of LZU-170 by 60% in 20 s;and with the electron donor has a certain fluorescence enhancement effect,which 4-chloro-anisole in 90 s can enhanced the fluorescence of LZU-170 by 20%.And the fine adjustment of the material structure has an effect on the fluorescence recognition effect.