Covalent-Organic Polymers As Luminescent Probes

The fluorescent research of Metal-organic frameworks (MOF) and Covalent Organic Materials (COM) have attracted more attention recently. They have been widely applied to the hydrogen storage, adsorption separation, catalyst, fluorescent sensors, but the selectivity and sensitivity of MOF and COM in fluorescence sensing performance are not high. In this thesis, we synthesized four covalent organic polymer materials. They not only have good hydrothermal stability, because their structures contain a large number of conjugate systems. Therefore, they can be used as sensing materials. The main content of this thesis are as follows:(1) We have synthesized four COPs((COP-401, COP-405, COP-301, COP-305) by using Yamamoto-type Ullmann reaction catalyzed by Ni, and performed a series of characterization for the COPs. The Fourier transform infrared (FTIR) measurement indicates that the reaction is successful. The TGA indicates that COPs are highly thermal stability. The SEM images show appearance characteristics of COPs, and COP-401 and COP-305 show hollow pipe morphology, while the COP-301 and COP-405 exhibit spherical shape. The solid-state photoluminescence (PL) spectra of the COPs shows stronger fluorescence intensity than their organic ligands.(2) These four COPs have been used as promising luminescent probe to detect different metal ions (Fe3+、Cu2+、Co2+、Ni2+、Cr3+、Mg2+、Pb2+ Cd2+). The fluorescence intensity is different for different metal ions and the quenching effects of the COPs for Fe3+　are very apparent. In addition, the quenching effects are enhanced with the increase of Fe3+. The fluorescence intensity of COPs almost have no change with the effect of anions (SO42-, F, NO3-,S2-, CO32-). Further research shows that the fluorescence intensity of COPs are related with their solvent, and is different under different organic solvents (DMF, DMAC, THF, CHCl3, Toluene, Acetone, EtOH, MeOH)(3) These four COPs have also been used as promising luminescent probe to detect nitroaromatic explosives, and all COPs show luminescence quenching effects for nitroaromatic explosives, and exhibit high selectivity and sensitivity for 2,4,6-Trinitrophenol.(4) By introducing different functional groups, we have prepared several COPs with functional groups (TBT+DB-COOH, TBT+DB-CHO, TBT+DB-SOCl, TBT+DB-NH2, TBT+DB-NO2, TBT+DB-N, TBT+DB-OH). The fluorescence intensity of functionlized COPs are different from COP-401. However, these functionlized COPs show promising properties as luminescent probe to selectively detect different metal ions (Fe3+、Cu2+、Co2+、Ni2+、Cr3+ Mg2+、Pb2+、Cd2+)...