Design And Properties Of Photochromic Material:Schiff–based Naphthopyran

Naphthopyrans?NPs?as animportant photochromicsystem has good resistance fatigue,remarkable photoresponse and breadth of generated color.Now,people study the photochromic performance of Naphthopyrans more than other performances.In recent years,Schiff base is very easy to form complexes with metal ions,which made them very useful in many fields.In particular,Schiff base as a fluorescent sensor can detect small molecule or heavy metal ion.In this work,we designed and synthesized a novel naphthopyran derivate.This proposed compoud presentedmultiply functions such as photochromism,fluorescence emission andfluorescence sensing for Cu²⁺.We used MS and 1H NMR to characterize the molecular structure properties of nover Naphthopyrans.Light responsive properties were characterized by fluorescence spectra and UV-Vis.The main content as following:1.We designed and synthesized a Schiff base?NP-DAMN?by the reaction of naphthopyrans and diaminomaleonitrileand used MS and 1H NMR to characterize the structure properties of NP-DAMN.2.UV-Vis absorption spectrashowed thatNP-DAMN has good photochromic performance and presents remarkable photoresponse and resistance of photochemical fatigue.3.NP-DAMN for Cu²⁺ as a colorimetric sensor that yellow will fade after was coupled with Cu²⁺.So NP-DAMNcan detect Cu²⁺ by the naked eye.4.Because NP-DAMN had strong fluorescence emission,so NP-DAMNdisplayed “on-off” fluorescent sensing for Cu²⁺withhighselectivity and sensitive.The fluorescenceof NP-DAMN was almost quenched in CH₃ CNsolution upon the addition of 4.0 equiv Cu²⁺.