Synthesis And Spectral Properties Of The Carbazole Based Intramolecular Charge Transfer Compounds

The charge transfer process is one of the most basic process in physical, chemical and biological process. Photo induced intramolecular charge transfer (ICT) is one of the hot topics which is concerned by scientists in recent years. Due to the rapid development of electron transfer theory, and the emergence of ultrafast laser technology, the research of photochemistry made a great breakthrough in the fields of theoretical knowledge and experimental techniques, so the ICT photochemical for research in the field of optoelectronic materials and supramolecular recognition has attracted much attention.Carbazole has special rigid planar structure and good fluorescence emission with strong electron donating ability and the hole transport properties. The 3-,6-,9-positions of the molecules can easily be modified by chemical reaction. Better hole transport materials with higher HOMO level can be obtained by introduce other substituents to adjust the molecular structure, and modulating the properties of compounds, and decrease the initial oxide potential of compounds. So carbazole is an important material for synthesis of intramolecular charge transfer compounds.Chapter 1:The type, property and characteristics of charge transfer compound were described briefly. The classification, theoretical model and application of intramolecular charge transfer compounds were summarized. The research progress and application of carbazole and its derivatives were reviewed briefly.Chapter 2:A new three carbazole conjugate compound with the characteristics of ICT was synthesized. The research results of UV-Vis spectra and fluorescence spectra properties proved that the compound has obvious ICT characteristics. We investigated the fluorescent spectra in different conditions such as concentration, pH value. The fluorescent quantum yields of the compound in different solvents were determined. The results showed that the compound has high quantum yield, and the excited state has a larger cross-sectional area, so that it can be used for the study of two-photon absorption materials.Chapter 3:Three kinds of ICT compounds were synthesized by modifing three different conjugated molecules on carbazole, and the spectral properties of the compounds were studied, the effects of solvent polarity to the compound spectra were investigated, the changes of ICT excited state dipole moments of △μ was calculated out through Lippert-Mataga equation computation, the possible ICT process was discussed. We expect to adjust the photoelectric properties of carbazole molecule by modifying the group, and obtain better functional organic moleculeChapter 4:Two new compounds were synthesized by using carbazole and fluorene as the basic unit and connected through conjugated bridge in one molecule, the structures of the two compounds belong to symmetry and asymmetry respectively. And the spectral properties of the two compounds were investigated, the results showed that two compounds were unstable, and the luminescent properties were poor compared to other synthesis of carbazole derivatives.Chapter 5:Three kinds of asymmetric single substituted carbazole based compounds were synthesized, and spectroscopic properties of the compounds were studied. The effects of solvent polarity on the compound spectra were investigated, the change of ICT excited state dipole moments of △ μ was calculated by Lippert-Mataga equation, the different property of two kinds of carbazole based compounds were compared, heterocyclic substituted compound showed better performance of luminescence, the experimental results provide the compounds a theoretical basis for the application in photoelectric materials.Chapter 6:A compound with good fluorescence properties was synthesized by chosing benzo indole as a modified group and connecting with the carbazole through conjugated bridge. The spectral properties of the compound was studied. This compound has a reversible response to H+, so it has potential to use as H+ probe.Chapter 7:All the works in the dissertation are summarized, and put forward a plan for the next work. The patent content is briefly introduced, mainly about solid fluorescence writing materials, compared to the traditional solid writing materials the solid fluorescencd writing material have many advantages. The color of this crayon bright with fluorescence, harmless to the human body, no pollution to the environment, it can be cleaned use water or soap. It can be used for writing, drawing or marking.