Synthesis And Photochromic/Thermochro-mic Properties Of4-substituted Benzoyl Pyrazolones

Organic photochromic materials have received extensive attention and researchesat home and abroad for its unique performance in military and civilian fields, such asoptical information storage, optical switching, security and protection, etc.Pyrazolone derivatives have received an extensive concern because of its uniquephotochemical properties. This paper according to the previous work in our laboratory,a series of pyrazolone derivatives have been synthesized though introducing electronwithdrawing group on benzal of the4-position of pyrazolone-ring. The study foundthat compouds with different substituents at benzene ring have different properties.Some compounds have photochromic properties, and some of compounds exhibitthermochromic properties. Their structure was determined by IR,1H NMR spectraand mass spectra. And the photochromic/thermochromic properties were studied inthe solid state.Chapter one, six new novel compounds:1,3-diphenyl-4-[3,5-(bistrifluoromethyl)/(dinitro)benzoyl]-5-hydroxypyrazole semicarbazones/thiosemicarbazones compound-s were synthesized. Thereinto, compound DP3,5NO2BP-PSC exhibitsthermochromism. The synthesized compounds were all characterized by IR,1HNMRspectra and mass spectra. The photochromic/thermochromic properties were studiedby UV-Vis spectra and fluorescence emission spectra. The mechanism were discussedand analysized by crystal structure and spectroscopic data.Chapter two, six new novel compounds:1,3-diphenyl-4-[3-fluoro-4/5-(trifluoro-methyl)benzoyl]-5-hydroxypyrazole semicarbazones/thiosemicarbazones compoundswere synthesized. Thereinto compounds DP3F4TFBP-PSC, DP3F4TFBP-MTSC andDP3F4TFBP-ETSC exhibit reversible photochromism. The synthesized compoundswere all characterized by IR,1HNMR spectra and mass spectra. The photochromicproperties and thermal fade were studied by UV-Vis spectra and fluorescenceemission spectra. Chapter three, we selected the compound DP3F4TFBP-PSC which has goodphotochromic properties as the dopant, and the polymerHydroxypropylmethylcellulose(HPMC)as the film-forming material. The pyrazolone/HPMC composite films were prepared by flow casting and spin coating. The SEMwas used to observe the surface morphology characteristics of composite film. Thephotochromic behaviors, thermally fade behavior of composite films werecharacterized by the UV-Vis spectra, and comparing with the pure compound. Theresults show that, compound which dopping in the film exhibit the similar propertiesare consistent with the pure compound. Besides, we also prepared theDP3,5NO2BP-PSC/HPMC composite film, but the composite film haven’t exhibitthermochromism, and explored the reason preliminary.