Syntheses And Properties Of Functional Materials Based On Imidazo[1,2-a]Pyridines

This thesis reviewed the research progress of organic radical functional material with special structures, carbon materials and functional organic micro/nano materials. During previous research, our laboratory has synthesized a series of organic radical functional materials based on imidazo[1,2-a]pyridines, which have good stability, interesting optical and magnetic properties.We used imidazo[l,2-a]pyridine-2(3H)-one to react with3-formyl-2,3’-biimidazo[1,2-a]pyridine-2’one (obip-CHO) radical, leading to a new stable diarylmethyl monoradical through one-pot reaction. This monoradical can be easily transfered into a stable diarylmethyl triradical in which there exists a special proton-shared hydrogen bond. Because of the proton-shared hydrogen bond, the quantum yield of triradical reaches31%. Moreover, reversible color, luminescent and magnetic transformation between triradical and monoradical stimulated by acid and ammonia vapor avails to develop dynamic multifunctional materials. Responsiveness of triradical to ammonia vapor stimulus makes it potential for phosphorescent and magnetic ammonia gas sensing. This work also provides reference for synthesizing new stable diaryl-methyl (-alkyl) radicals and preparing new sensing materials.Based on the successful using imidazo[1,2-a]pyridine-2(3H)-one as substrate to explore new reaction, we expanded this substrate to react with furfural which is a widely existing biomass product. By simple aldol condensation reaction between imidazo[l,2-a]pyridine-2(3H)-one and furfural, to our surprise, under the mild condition, the spherical nitrogen-containing carbon materials were prepared through a radical polymerization/carbonization process. If surfactant (sodium dodecyl sulfate) was added into the above reaction system, nubbly nitrogen-containing carbon materials will be prepared. Compared with spherical nitrogen-containing carbon material, coercive force of nubbly nitrogen-containing carbon material is obviously enhanced, showing interesting morphology-relative magnetic behavior which can be attributed to the morphology anisotropy of nubbly nitrogen-containing carbon material. This work would provide novel nitrogen source and very simple route for the preparation of nitrogen-containing carbon materials.Preparing organic small molecule micro/nano materials through non-covalent interactions is a hot field but is relatively less researched. We take advantage of the derivative of obip-CHO and acetophenone:(E)-3-(3-oxo-3-phenylprop-1-enyl)-2,3’---biimidazo[1,2-a]-pyridine-2’(3-H)-one radical (OPBIPO), a two dimensional (2D) micro/nano material was facilely fabricated with the help of P123surfactant. The results demonstrated that compared to the bulk OPBIPO counterpart, the coercive force of2D OPBIPO microsheet sample is enhanced, which can be attributed to the morphology anisotropy of microsheet structures. In addition, the photo luminescence spectra show that the emission intensity of the microsheet sample is higher than that of the bulk material. This surfactant-assisted self-assembly technology will provide useful information for the fabrication of organic radical microstructures with novel morphology-dependent magnetic behaviors.