Research On High-performance Organic Second-order Nonlinear Optical Materials With D-π-A Configuratio

In the fast developing information network era,the storage capacity of electronic information is limited.In order to meet the human requirements for the quantity and speed of information storage,many optical storage materials have been designed and synthesised.However,the information transmission system using electrons as the information carrier still has many shortcomings,such as slow speed and large size,which hinders the development of the electronic information era.Organic electro-optical materials are a kind of organic materials that can realise the mutual transformation between electric field and light wave through electric field,and can realise the functions of electro-optical switch and electro-optical frequency conversion.The optical folding properties of organic materials can be flexibly modulated to give them higher information density and faster transmission rates.Non-linear optical chromophores are an important component of organic second-order non-linear optical materials,so the design and synthesis of high-performance organic second-order non-linear optical chromophores with D-π-A configuration is a major strategy to improve the thermal stability and electro-optical properties of electro-optical materials.In this paper,we focus on the design and synthesis of high performance organic second-order non-linear optical chromophores with D-π-A configuration,the effect of different modification groups on the electro-optical activity of chromophores and the preparation and properties of cross-linked electro-optical material systems.The following results were obtained:(1)Twelve D-π-A conformational nonlinear optical chromophore chromophores 1-12 were designed and synthesized based on 12 different electron donors,using isophorone derivatives as π-electron bridges,linked to TCF(2-dicyano-methylene-3-cyano-4,5,5-trimethyl-2,5-dihydrofuran).The effects of different donors on the properties of the chromophores were revealed.It is shown that the introduction of one or more heteroatoms can effectively increase the electron-donating ability of the donors,thus increasing the first hyperpolarization rate of the chromophores and thus obtaining a larger electro-optic coefficient.(2)Based on the study of cross-linked chromophores,the Diels-Alder cycloaddition crosslinked chromophores SLD1 and FLD1-2 were designed and synthesised using a single donor derivative(4-((2-hydroxyethyl)(methyl)amino)benzaldehyde)and a salicylic aldehyde derivative(4-(diethylamino)-2-hydroxybenzaldehyde),and the effects of different electron donors and cross-linking methods on the electrophotographic properties of the chromophores were investigated in detail.The effects of different electron donors and cross-linking methods on the electro-optical properties of the chromophores were investigated in detail.The chromophores SLD1 broke the binary cross-linking feature,and the glass transition temperature reached 154°C after cross-linking of the mono-cross-linked chromophore SLD1,while the Tg reached 160°C after cross-linking of FLD1 and FLD2.The high thermal stability provides a favourable basis for commercialisation.(3)The Diels-Alder cycloaddition and Huisgen 1,3-dipole cycloaddition chromophores of the D-π-A configuration QLD3-6 were designed and synthesized based on tetrahydroquinoline derivatives(1-(2-hydroxyethyl)-2,2,4,7-tetramethyl-1,2,3,4-tetrahydroquinoline-6-carbaldehyde)as electron donor by introducing different modification groups.After crosslinking,the After cross-linking,the glass transition temperature of QLD5-6 chromophores reached 152 °C and the electro-optical coefficient was as high as 351 pm/V.The chromophores have high electro-optical activity and are organic electro-optical materials with excellent performance,which are expected to be used in commercial production.