Synthesis And Properties Of Novel Photochromic Diarylethene With Terpyridine Unit

Due to excellent thermal stability and fatigue resistance, in the army of organic photochromic compounds, diarylethenes are particularly prominent. So far, it has emerged as a new research hotspot for chemical sensor, the synthesis of diarylethenes which have a unique response for ions have been extensively investigatedThis paper introduced the terpyridine unit into diarylethenes, and synthesized8new asymmetric photochromic compounds. Their structures were characterized by NMR, UV and IR. The photoelectric properties and metal ion recognition of photochromic compounds were investigated in detail. In addition, two novel diarylethenes bearing same heterocycle with different substituent group have been synthesized to investigate the effects on photoelectrical properties. The main content of this paper summarized as follows:In chapter1, the basic concept, principle, and classification of photochromic compounds are expounded. The application and latest progress of diarylethenes are intensively introduced.In chapter2, six compounds containing terpyridine unit DT-1-6were designed and synthesized. All the diarylethenes exhibited good photochromic properties in dichloromethane, and by the addition of Hg(II), the fluorescence performance of DT-1-6was not the same. The fluorescence intensity of DT-1-6was significantly enhanced and red-shifted except DT-4, especially the intensity of DT-5and DT-6increased34times and20times respectively. And the fluorescence intensity of DT-1-6complextion with Hg (II) could be quenched by EDTA.In chapter3, two asymmetric compounds containing terpyridine unit DT-7-8were designed and synthesized. The results found that DT-7-8only responded to Hg(II) and red-shifted. At the same time, the intensity of DT-7and DT-8increased eleven times and four times respectively.In chapter3, DT-9-10were designed and synthesized. The optoelectronic properties of DT-9-10were investigated in acetonitrile, such as ultraviolet absorption, molar extinction coefficients and fluorescent spectra. The fluorescence intensity of DT-9-10exhibited relatively clear fluorescent switches both in acetonitrile solution and PMMA film upon altering irradiation with UV and visible light, and the fluorescence intensity of DT-10was relatively strong.