Synthesis And Optical Properties Of Compound Naphthopyran-Curcumin

With the advent of the information age, the storage capacity and storage speed of information have become two major challenges in the development of information storage technology. Recently, it is found that organic photochromic material with light sensitivity, high storage density and good fatigue resistance has become the ideal material for information storage. In order to further meet the demands for organic photochromic material in different fields, developing new photochromic material seems to be particularly important. Based on the above background, we synthesized a new photochromic fluorescent compound and then researched the optical properties,the details are as following:(1) A novel molecule which contains two photochromic naphthopyran moieties linked to a fluorescent curcumin has been prepared and was abbreviated as NP-C-NP. After the target compound was characterized by 1H NMR, the fluorescence photoswitch property and photochromic property of compound NP-C-NP were investigated by the fluorescence spectra and UV spectra in PMMA film and acetonitrile solution. We found the fluorescence intensity of NP-C-NP could be adjusted reversibly under the UV/visible light irradiation alternately through the photochromic behavior of NP components. At the same time, NP-C-NP shows favorable photochromic properties and good fatigue resistance. Then the photochromic properties of NP-C-NP was further studied by decolorization kinetics.(2) To explore the influence of the naphthopyran component to the solvatochromic properties of curcumin in different solvents, comparative analysis of the ultraviolet spectra and fluorescence spectra was implemented. It is shown that naphthopyran component can inhibit the solvatochromic properties of curcumin. In addition, we found the Stokes’ shift of both NP-C-NP and curcumin increasing with solvent polarity, and the Stokes’ shift of NP-C-NP increases slower than the later one. What is more, dipole moment change(Δμ) and quantum efficiency(Φf) of NP-C-NP are generally less than those of curcumin.