Synthesis And Photoelectric Properties Of Diarylethene Photochromic Dimer Derivatives

As a new type of photochromic material,Diarylethene Derivatives has many potential application in information storage, biological probes, light control switch and so on. Scientists constantly try to design and synthesis more superior classes of Diarylethene Photochromic Materials with high performance, and try to apply them to different areas. This paper synthesized two kind of Photochromic Diarylethene Compounds (4b and 12):1. A flexible method for the synthesis of five tetra-substituted thiophene or furan compounds. The single crystal structure of tetra-thiophene 3b was obtained and analysized by X-ray diffraction. Respectively through Friedel-Crafts acylation and Michael addition, we synthesized a new type of Diarylethene Photochromic Dimer Compounds 4b, conformed and by IR, NMR and MS. Under the excitation wavelength 250 nm, a variety of 4b solution turned yellow from colorless and UV-Visible absorption indicated a new absorption peak around 410 nm. Changes in the differential pulse voltammograms of a CH2Cl2 solution of 4b as it is irradiated with 365 nm light showed that only one photochromic unit occurs cyclization, indicating that in addition to conjugation, there are other factors that affect the photochemical reaction process. With the increase of solvent polarity, the fluorescence of 4b showed blue shift and the maximum Stokes shift was up to 90 nm.when the concentration from 1.0×10-6 mol/L increased to 1.0×10-3 mol/L, the fluorescence is completely uenching. In addition the crystal structure of 4b also occurred photochromic phenomenon. Compounds 4b thermal decomposition temperature is much higher than 200 oC.2. Compound 12 is a potentially photochromic ligand. This chapter was using different synthetic strategies to obtain target ligand: A is by Friedel Crafts acylation reaction followed by Mcmurry reaction; B is by classical Suzuki coupling reaction. The development of route A is limited because of special Friedel Crafts reaction of pyridine; B line, using the classical Suzuki coupling reaction, have seen the target molecular weight and photochromic phenomenon (colorless to wine red) and therefore has a bright future.