Synthesis And Optical Properties Of Cyclopentadienyl Iron Complexes Containing Conjugated Benzyne And Carbazole Moiety

Conjugated phenylethynylcarbazole derivatives are important building blocks in the designing of functional materials for the conjugated rigid plane structure of carbazole and the properties of excellent electron transport in benzyne. Cyclopentadienyl iron complex is a kind of metal complexes with special photochemical and electrochemical properties. In this thesis, novel D-π-A-π-D cyclopentadienyl iron complexes containing benzyne and carbazole groups (CzFcs) were designed. The designed CzFcs possess the charge transfer ability and photochemical properties simultaneously. The main work in this thesis includes:Four CzFcs were synthesized via Sonogashira coupling reaction and nucleophilic substitution reaction using bromo-substituted carbazole and Fc-2C1as main raw materials, namely (η6-1,4-di(9-(3-phenylethynylcarbazolyl))benzene)((η5-cyclopentadienyl) iron hexafluorophosphate (MHCzFc),(η6-1,4-di(9-(3-(4-methoxylphenyl)ethynylcarbazolyl))benzene)((η5-cyclopentadienyl) iron hexafluorophosphate (MMoCzFc),(η6-1,4-di(9-(3,6-diphenylethynylcarbazolyl))benzene)((η5-cyclopentadienyl) iron hexafluorophosphate (DHCzFc),(η6-1,4-di(9-(3,6-di(4-methoxylphenyl)ethynylcarbazolyl))benzene)((η5-cyclopentadienyl) iron hexafluorophosphate (DMoCzFc). Then, four conjugated phenylethynylcarbazole derivatives ligands (CzFc-Ps) were obtained via the photolysis of CzFcs, namely1,4-di(9-(3-phenylethynylcarbazolyl))benzene (MHCzFc-P),1,4-di(9-(3-(4-methoxylphenyl)ethynylcarbazolyl))benzene (MMoCzFc-P),1,4-di(9-(3,6-diphenylethynylcarbazolyl))benzene (DHCzFc-P),1,4-di(9-(3,6-di(4-methoxylphenyl)ethynylcarbazolyl))benzene) (DMoCzFc-P). All the compounds synthesized in this thesis have been fully characterized by IR,1H NMR,13C NMR and MS. The optimized structures and frontier molecular orbitals have calculated by quantum chemistry.The UV-vis spectra and fluorescence spectra of CzFcs and CzFc-Ps have been studied. The U V-vis spectra of CzFcs showed that the complexes have a strong absorption above300nm. All the CzFc-Ps exhibited strong fluorescence with large quantum yield. DMoCzFc-P has the largest quantum yield (up to0.63) among them. Meanwhile, the fluorescenc quantum yields of CzFcs are smaller than that of CzFc-Ps.Two-photon excited fluorescences of CzFc-Ps have been investigated under femtosecond laser in the range of720-790nm. The results showed that all of them exhibit the ability of two-photon absorption properties. The values of two-photon cross section of DMoCzFc-P, DHCzFc-P, MMoCzFc-P and MHCzFc-P are448GM,371GM,66GM and41GM, respectively.The photoinitiating activities of CzFcs have been studied via photo-NIR technique using halogen lamp as light source, which indicated that all of them exhibit good photoinitiating activities due to the sensitization of carbazole group. The result shows that DMoCzFc exhibits the best photoinitiating ability among them.