Synthesis And Properties Research Of New Visible Light Triggered Donor-acceptor Stenhouse Adducts Photochromic Materials

Organic photochromic molecules are one of the most rapidly developed dyes in recent years,especially a new type of visible light triggered photochromic unit DASAs(Donor Acceptor Stenhouse Adduts)have been found.After being irradiated by visible light,the compounds gradually change from colored to colorless,and simultaneously from hydrophobic to hydrophilic.In this paper,we developed some new donor and acceptor units to regulate the molecular structure of DASAs,as follows:Firstly,the single substituent acceptor with different electron effect was introduced in the acceptor of DASAs molecule to study the influence of different electronic effects,and other factors on the photochromic properties and the maximum absorption wavelength of DASAs molecules.Secondly,by introducing some fluorescent groups such as tetraphenylethylene into the donor or acceptor part,we can study the change and mechanism of fluorescence regulated by visible light.Firstly,barbituric acid derivatives substituted by N-derivatized tetraphenylethylene were synthesized,and DASAs molecules were obtained by ring opening reaction with different secondary amines,which showed good photochromic properties under visible light.In addition,the reaction activity,discoloration rate,solvent effect and fluorescence regulation were studied in detail.And,we also synthesized the tetra/pental-phenylethene indoline derived the third generation of DASAs.A new type of fluorescence switch excited by visible light was constructed and the AIE phenomenon under the excitation of visible light was explored.The molecule also shows good fluorescence regulation ability and it is a potential erasable and rewritable photochromic material.Thirdly,we designed and synthesized a new type of DASAs photochromic functional dye with multi-driving response of UV and visible light.By modifying the donor or acceptor structure of DASAs molecule,and introducing other high-performance photochromic groups such as diarylethene,we have studied the synergistic effect between DASAs group and other photochromic groups.The UV photochromic materials of diarylethene and DASAs were connected by indoline bridge successfully.The molecular is responsive to UV light,visible light and heating,and can realize the continuous change from blue to colorless to purple.It will be widely used in anti-counterfeiting materials and other fields.