Design, Synthesis And Optical Performance Of Benzoxazinone Derivatives And Triazole Derivatives

Excited-state intramolecular proton transfer(ESIPT) is identified as a prototype of proton-transfer reactions and is the most fundamental process for chemistry and biochemistry. Various ESIPT molecules have been obtained such as benzophenones, azoles and salicylidene anilines and the basics of ESIPT process have also received a great maturity through the massive volume of reserch works. Despite of such developmennts, owing to its inherently H-bond and nuclear rearrangement, controlled synthesis and detailed machanism have huge challenges. At present, design and synthesis of new molecules and detailed mechanism analysis are two main aspects for ESIPT research. Hydroxyflavon derivatives are representative materials exhibiting ESIPT and the classical example is 3-hydroxyflavone(3HF). In this paper, we design and synthesize three benzoxazinone derivatives CC, CB and CA2. The molecular stuctures of these compounds are similar to 3HF. Benzoxazinone derivatives have anti-platelet aggregation activity and are main used in medicines, pesticides and dyes now. Compared with 3HF which have been widely investigated in ESIPT, there is less relevant literature about ESIPT in this system. Meanwhile, with CC as intermediate, we designed and synthesized three triazole derivatives CCN1-COOH、CCN1-CF3、CCN1-Br and CCW. CCN1-COOH exhibits reversible piezochromism and acidchromism properties and CCN1-CF3 can used as metal ion probe. Specific contents about this thesis as follows:1) Organic molecular CC exhibiting ESIPT was designed and synthesized, and detailed mechanisms have been investigated by a combination of theoretical calculations and experimental measurements. Its aggregation-induced emission(AIE) phenomenon、solvent effect and viscochromism are also studied. Introduce benzene ring to the different position of compound CC, we obtain two isomers CB and CA2 and study the effect of substituent position on ESIPT experimentally and theoretically. For compound CB, aggregation-induced emission enhanced(AIEE) and the effects of concentration and viscosity on emission color are researched.2) With CC as intermediate, we synthesize triazole derivative CCN1-COOH and find that it exhibite reversible piezochromism and protonation stimul-response characteristics. Fluorescence quantum yeild(ΦF) of pristine crystal is 35% and upon grinding, a significant blue-shift occured and the ΦF increased to 55%. Fumigation with organic solvent vapor, the emission color recovered. When CCN1-COOH is exposured to HCl or TEA vapor, the fluorescence of the crystal changed from orange light to blue light in different degree. Based on a variety of spectroscopic techniques including IR, SEM, XRD and Time-resolved fluorescence spectrum, the observed piezochromic emission is related to the loose intermolecular packing and the change of the lattice. And the deprotonation of-COOH and-OH group in CCN1-COOH has a significant effect on the frontier molecular orbitals and further causes the protonation effect. We also synthesize other three compounds CCN1-Br, CCN1-CF3 and CCW that contains different substituents and make a rough study of the stimuli-response properties. In conclusion, we speculate that the loose intermolecular packing and the change of the lattice intermolecular bonds work together to induce the piezochromism.3) In the research above, we find that CCN1-CF3 and CCN1-Br could be used as fluorescent probe to detect Al3+ and Zn2+. Besides, we known that CCN1-CF3 gone ESIPT process through testing Uv-vis absorption spectra and fluorescence emisson spectra in different solvents.