Study On Synthesis, Crystal Structures And Photochemical Properties Of Pyrazolone Thiosemicarbazones

Photochromic material is a new kind of functional material that has the special photochemistry property. And these materials are of great interest science they have extensive potential use both in daily life and in high technique field, such as dyes, ophthalinic lenses, photoswitches, optical storage and memory devices, and so on. Though many of photochrimic compounds exemplified photochromic reactivity in solution, there are not so much reported that have show good photochromic in solid state. This makes it a great limit to the development application of the material. On the basis of previous research, derivatives of pyrozolone could carry on photochromic reaction and have greater prosperities in kinds of applications. As a result it means much to research of the relation between the photochemistry properties and theories, structures and the functions of mechanism. Several novel thiosemicarbazones compounds containing pyrazolone-ring have been synthesized. The spectral changes of UV-Vis and fluorescence for the compounds were analyzed in solid state and in solution separately. The photochromic mechanism was discussed and presumed by analyzing the properties and crystal strutures of the photochromic compounds. The relation between the structure and properties has been obtained. The main results were shown as bellow: 1. Seventeen different novel compounds were designed and synthesized and they are: Series1:five semicabarzones containing l,3-diphenyl-4-(4'-flurobenzal)-5-pyrazolone (DP4FBP-SC, DP4FBP-PSC, DP4FBP-TSC, DP4FBP-MTSC, DP4FBP-ETSC). Series 2: three semicabarzones containing l-phenyl-3-methyl-4-(2'-flurobenzal) -5-pyrazolone (PM2FBP-SC, PM2FBP-TSC, PM2FBP-MTSC). Series 3: five hydrazones and acylhrdrazones containing 4-acyl pyrazolone (DP4FBP-SAL, DP4FBP-SAH, PM2FBP-SAH, PMPP-SAL, PM2FBP-SAH). Series 4: four semicabarzones containing l-phenyl-3-methy]-4-propenbenzal -5-pyrazolone (DP4FBP-SHN, PM2FBP-SHN, PMPP-TSC, PMPP-MTSC). 2. We carried out detailed study on the photochromic properties in solid state and find that all the compounds except PM2FBP-SC of series 1 and 2 express good photochromic phenomena, while PM3CBP-SHN and PM2FBP-SAH possess photochrimic property to some extent. The compounds DP4FBP-SC and DP4FBP-PSC have fast velocity in the photochromic reaction and good reversibility and reduplication. By discussing the influence of different factors, the reasons to...