Synthesis, Electric Structures And Properties Of Some Novel Schiff Bases With Pyrazolone

The Schiff base with photo- and thermochromic properties for its special structure of tautomers(keto and enol) has been applied in many fields, such as high density optical memories, molecular switching devices, nonlinear optical devices and liquid crystal alignment, and so on. Meanwhile, pyrazolone compounds have many advantages, such as easy to be modified, synthesized, tailored and extended. In this dissertation, we adopted a strategy, introducing the Schiff base containing pyrazolone with another optical block by different ways, to realize novel foundational materials, and give an emphasis to the study on theirs electric structures and photoelectric properties.Three novel Schiff bases containing two optical functional blocks were synthesized: 1-phenyl-3–methyl–4–benzoyl–5–pyrazolone N-amino-carbazole (S2), 1-phenyl-3–methyl– 4– benzoyl–5–pyrazolone N–benzyl–carbazole (S3) and 1-phenyl-3–methyl–4–benzoyl–5– pyrazolone N-anilin-4-piperidine-1, 8-naphthalimide (S4). Meanwhile, 1-phenyl-3–methyl–4– benzoyl–5–pyrazolone aniline (S1) was synthesized as a reference. Theirs molecular structures were confirmed by FT-IR and 1H NMR, and the conditions of the synthesis were discussed.The UV-vis spectroscopic of S1, S2, S3 show that two conjugate structures (N1-N2=C3 of pyrazole ring and C6=N3 of Schiff base) are included in S1. Besides, another conjugate structure is emerged in S2 and S3, owning to the join of carbazole group. Interaction among the three conjugate structures was observed by UV-vis spectroscopic. Luminescence quenching observed in luminescence spectrum indicates that the electron transfer occurred between two functional blocks. While, the character peaks of carbazole and pyrazolone in the luminescence spectrum of S3 suggests neither electron transfers nor energy transfers between them. As discussed before, the reason is that the transfer of electron and energy has relations with the distance between two functional groups. With the increase of the concentration, the formation of the interaction will vary from electron transfer to energy transfer, even to the interaction too weak to influence each other.Electronic structures and photoelectric properties of S4 in different concentrations and solution (DMF, acetone, THF and toluene) have been studied with emphasis. The results show that the electronic structure and the character of luminescence are varying with the solution and the concentration. For the structure of Keto, the character peaks of pyrazolone were observed in the Luminescence spectrum of S4 in the lower concentration solution. On the contrary, when the tautomers changes to Enol, S4 resemble the naphthalimide in the...