Synthesis And Property Of Novel Tetrasubstitated Imidazoles Containing Allyl And Their Polymers

Imidazole polymer possesses satisfactory comprehensive performance in chemical property, thermal stability, mechanical property and optical property, because of its unique structure. Therefore, imidazole polymer was widely applied in many fields and played a very important role in the fields of catalysis, organic photoelectric and aerospace materials. In this paper, novel imidazole polymers were designed and synthesized by radical polymerization on the basis of designing and synthesizing for rarely reported 1-allyl-2,4,5-tetrasubstituted imidazoles. Then, the UV and fluorescence spectra of the polymers were tested and the quantum yield was calculated. Besides, their thermal stability was studied.First of all, ten kinds of 2,4,5-trisubstituted imidazoles were synthesized using solvent-free microwave-assisted technology, and the structures of derivatives were confirmed through IR, high resolution mass spectrometry and nuclear magnetic resonance hydrogen spectrum(1H-NMR). The influences of different substituents on the yields were investigated. Then the UV and fluorescence spectra of nine kinds of the 2,4,5-trisubstituted imidazoles were tested, quantum yield was calculated. At the same time, the influences of different substituents on the quantum yields of the 2,4,5-trisubstituted imidazole derivatives were analyzed.Then, using home-made 2,4,5-trisubstituted imidazoles as matrix, a series of 1-allyl-2,4,5-tetrasubstituted imidazoles were prepared by conventional heating reaction with allyl chloride in alkaline condition. The structures of derivatives were confirmed through IR, high resolution mass spectrometry and nuclear magnetic resonance(NMR) spectroscopy. The effects of different substituents on the yields and the fluorescence quantum yields were analyzed. Also, the differences of luminescence property were investigated when allyl group was introduced on the 2,4,5-trisubstituted imidazoles compared with 2,4,5-trisubstituted imidazoles.Again, the polymerization condition of 1-allyl-2-phenyl-4,5-di(furan-2-yl)-1H-imidazole was explored by free radical polymerization. Poly(1-allyl-2-phenyl-4,5-di(furan-2-yl)-1H- imidazole) was successfully synthesized. Further, the polymerization condition was optimized by orthogonal experiment. The UV and the fluorescence spectra of polymers from orthogonal experiment were tested, and the quantum yields were calculated. Besides, the luminescence property and thermal stability were studied by detecting the fluorescence emission and DSC curve of tetrasubstituted imidazole polymers.At last, in order to study the applicability of polymerization method, other five novel imidazole polymers were designed and synthesized by the optimum polymerization condition, the structures of polymers were confirmed through the above characterization methods and the thermal stability was studied by the DSC curve. Besides, the UV and the fluorescence spectra of polymers were tested, and the quantum yields were calculated. Then the effects of allyl polymerized on the luminescence performance and thermal stability were investigated. The results showed that the conjugate degree and length of conjugated chain of 2- substituent on the imidazole was the key to affect the luminescence performance...