Structural Studies Of Novel Second-order Nonlinear Optics Based On Self-assembly And Pentafluorobenzene Acceptor

In the past 20 years,computer technology and communication technology have been rapidly developed,the terminal of the Internet has shifted from personal computers to mobile devices,and the form of information transmission has also developed from the past text to today's high-definition video,which has increasingly higher requirements for the transmission speed and stability of the Internet.In the past,the electrical signal had the disadvantages of large loss and low bandwidth,and it has been unable to meet the requirements of modern communication,and optical communication has the unique advantages of low loss,large bandwidth and strong anti-interference ability compared with electrical communication,so optical fiber communication has gradually become the mainstream communication technology.For electro-optic(EO)materials that carry electrical signals and optical signals to convert to each other,their performance is an important factor affecting the quality of Internet transmission.Organic nonlinear optical materials have the characteristics of large bandwidth,low half-wave voltage and fast response,so they have the prospect of practical application.In this article,a new organic second-order nonlinear optics(NLO)optical chromophore was synthesized and the thermal stability and optical properties of the material were characterized.The main work of the thesis is as follows:1.Three novel chromophores ARC 1-3 were designed with an aniline derivative as the donor,isophorone derivative as an electron bridge,and 2-(dicyanomethyl subunit)-4-methyl-5-phenyl-5-(trifluoromethyl)-2,5-dihydrofuran-3-carbonitrile(Ph-3F-TCF)as the acceptor.Their donors and electronic bridges are connected to three functionalized groups,anthracene,bisbenzyloxy and bis pentafluorophenethoxy,respectively.In this article,the electro-optical properties of the three chromophores of ARC 1-3 and ARC-1,3 and ARC-2,3 are compared,The electro-optical coefficients of pure chromophore ARC 1-3 are180 pm/V,157 pm/V,and 127 pm/V,respectively.ARC-1,3 and ARC-2,3 mixed into a film with electro-optical coefficients as high as 272 pm/V and 308 pm/V,respectively.This shows that supramolecular self-assembly between benzene/anthracene pentafluorobenzene effectively improves the stability of molecular orientation.In the case of high loading density,the force of ?-? stacking between benzene and pentafluorobenzene effectively inhibits the dipole force caused by the reduction of molecular spacing.2.No chromophores have been reported with 2-(dicyanomethyl subunit)-4,5-dimethyl-5-(2,3,4,5,6-pentafluorophenyl)-2,5-dihydrofuran-3-carbonitrile(Ar F-TCF)as the acceptor.In order to explore the electron-withdrawing capacity of Ar F-TCF acceptor and their effect on the properties of materials.Four novel chromophores H2,H3,H5,H6 were synthesized with acceptor Ar F-TCF and 2-(dicyanomethyl subunit)-4-methyl-5-(trifluoromethyl)-2,5-dihydrofuran-3-carbonitrile(Ph-3F-TCF).At the same time,these four chromophores also chose the electron bridge of isophorone derivatives with higher charge transfer efficiency and the julolidine derivatives and tetraethylmirenone derivatives donor with stronger electron supplying capacity.In this article,the electro-optical properties of four novel chromophores were compared by means of density functional theory calculations,ultraviolet absorption spectroscopy and electro-optical properties,and we also compared the chromophore H1 and H4 with 2-(dicyanomethyl subunit)-4,5,5-trimethylfuran-3-carbonitrile(TCF)as the acceptor.Through the calculation of density functional theory,it can be seen that the chromophore H2 of the Ph-3F-TCF receptor,the first-order hyperpolarizability of H5 is the largest,the electron absorption ability of the receptor is the strongest,the Ar F-TCF acceptor is the second,and the TCF receptor is the weakest.Although Ph-3F-TCF has the strongest electron absorption ability,H2 and H5 chromophores have a greater first-order hyperpolarizability,but the electro-optical coefficient is only 91 pm/V and 85 pm/V.This may be due to the stronger charge transfer capacity of the molecule,resulting in chromophore H2,H5 ultraviolet absorption peak redshifting and a cutoff wavelength of more than 1310 nm.This means that the material absorbs light from the operating band,thereby reducing the optical properties of the material.In contrast,the chromophores H3(245 pm/V)and H6(228 pm/V)with Ar F-TCF acceptor have stronger optical properties and are more suitable for application in the field of optical materials.