Design And Synthesis Of Organic-inorganic Hybrid Second Order Nonlinear Optical Materials Bearing Y-type NLO Active Chromophore

In recent years, Hybrid materials have found many uses such as abrasive resistant coatings, contact lenses, sensors, optically active films, and so on. Hybrid organic-inorganic materials through sol-gel process have been highlighted for their inherent properties of the silica matrix. The rigid silica network can provide an inert environment for organic molecules and prevent the relaxation of the non-centro-symmetric NLO chromophores alignment induced by an electric field.In this thesis, the basic theories of NLO is briefly introduced, molecular design theory and recent progress of inorganic-organic hybrid NLO materials are summarized in detail, based on which, a series of novel Y-type NLO chromophores a, b and c with imidazole or triazine heterocyclelarge are synthesized, the composite magnitude (β_CTμg) are 69.6, 144.0 and 37.9 (10^-30esu·D) respectively, which displayed higher melting point and better transparency. With 3-isocyanatopropyl triethoxysilance(ICTES), the highly NLO active choromophores successfully covalently bonded to form chromophore;alkoxysilane dye (ASD) A, B and C. All the structures of chromophores and ASD are confirmed by the ¹H NMR, MS, and IR. And the Transparency and thermal stability of compounds are detected by UV-Vis, TGA and DSCThree new organic-inorganic materials having organic chromophore were prepared by the sol-gel process with TEOS, and hybrid films were obtained by spin coating on the indium-tin oxide (ITO) glass substrates. The second-order nonlinear optical properties were characterized by using the maker fringe method after poling under the optimal poling condition. The d₃₃ of film with ASD B is 8.222 pm/V, whichis almost as larger as the reference film of DR1 (9.330 pm/V). And the CI33 of film with ASD A is 4.304 pm/V. So it is possible to increase the stability and optical nonlinearity by reasonable design of chromophore and ASD.