| The organic third-order nonlinear optical(NLO)materials,as key information media,have attracted considerable interests in the last two decades because of their potential applications in the development of photonic devices such as optical data storage,optical communication,and optical limiting.Metal organic nonlinear optical materials with the p-conjugated system have been investigated as alternatives to inorganic species due to their low cost,fast and large nonlinear response over broad frequency range,inherent synthetic flexibility,high optical-damage threshold,and intrinsic tailorability.Based on the evaluation of the bibliographer,the relationship between the molecular structure of organometallic color materials and the principle of molecular design were reviewed.Ferrocenyl organometallic color materials were designed and synthesized with ferrocene as organic fanctional group connecting with organic chromophore.Four series of 54 novel ferrocenyl organometallic color materials,vinylferrocene compounds,ferrocenyl Schiff Base,ferrocenyl formamide compounds and carbonyl ferrocene compounds,were designed and synthesized in the dissertation.The relationship between molecular structure and the third-order NLO properties were discussed.A series of 14 vinylferrocene organometallic color materials were synthesized starting from ferrocenecarboxaldehyde,alcohol,and triphenylphosphonium bromide in a one-pot process,solid-state reaction avoiding the synthesis of phosphorus ylides.The yields were 20.1-85.5%.A series of 16 ferrocenyl Schiff Base organometallic color materials were synthesized starting from ferrocenecarboxaldehyde and aromatic amine with the yields of 12.3-82.3%.A series of 16 ferrocenyl formamide organometallic color materials were synthesized starting from ferrocenecarboxylic acid and aromatic amines with the yields of 20.4-77.5%yields.A series of 8 carbonyl ferrocene organometallic color materials were synthesized starting from aroyl chloride and ferrocene with anhydrous aluminum chloride as catalyst.The yields were 10.8-67.7%.The structures of 54 desired color materials were identified and confirmed by UV,1H NMR and MS.The synthetic methods and mechanisms of reaction were studied.The process parameters were evaluated experimentally.The third-order NLO properties of four series of 41 novel ferrocenyl organometallic color materials were measured with the geometry of Degenerate Four-wave Mixing(DFWM)technique.Femtosecond laser pulses from Ti:Sapphire laser(800 nm,80 fs pulse width and 1 kHz repetition rate)were utilized for the experiment.The third-order NLO susceptibilities x(3),the second-order hyperpolarizabilities of the molecules y,the nonlinear refractive indexes n2 and the response times ? were calculated.The results showed that the x(3)of materials were 2.567-8.069x10-13 esu,the y were 0.853-2.681x1O-31 esu,the n2 were 4.735-14.852x10-12 and the ? were 33.96-97.57 fs.Based on the results of testing and conclucation,the relationship between the molecular structures and the characteristics of the third-order optical nonlinearities were studied.The results indicated that the D-?-A structures are the key function groups for the materials to improve their third-order NLO properties owing to the electron withdrawing effect in the other end of molecules.And the y value is up to 3.57 times of that of ferrocenyl structure.The formation of ferrocenyl D-r?-A configuration by introducing some electron-withdrawing group into the end of the material molecules,enhances the intramolecular electron mobility,increases the degree of electron delocalization,enhances the degree of intramolecular charge transfer,reduces the energy difference between HOMO and LUMO track,and conduces to improve the materials' third-order nonlinear properties.The influence of conjugate bridges on the third-order NLO properties decreases as follows:carbonyl,formamide conjugation,Schiff bases,and ethylene.At the same time,the molecules with strong D-?-A structures,conjugate bridges have more powerful effects on enhancing the third-order nonlinear properties of the molecular.On the other hand,introducing N,S,O and other heteroatom into the materials molecular can enhance intramolecular electron mobility,reduce material molecules d-?*transition energy,therefore improve the materials'third-order NLO properties.In addition,the ferrocene materials with asymmetric structure can cause the third-order NLO response under light excitation easier than those with symmetric structure,owing to the uneven distribution of the charge in the molecular and the high electron density at the ferrocene end.Therefore,the asymmetry structure of the molecular of materials will help to improve the y value of the second-order molecular hyperpolarizability.The ferrocenyl organometallic color materials have a very small response time,mainly in 30?60 fs,with the fastest up to 33.96 fs.The materials synthezed are a kind of prospective third-order nonlinear optical materials in photonic switching and optical computing. |
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