Synthesis, Properties And Microfabrication Of Two-photon Initiators With Multibranched Structure

Strong two-photon absorption (TPA) materials have wide and tremendous potential applications. A series of novel compounds as two-photon free-radical initiators with symmetric structural character of A-Ï€-D-Ï€-A and as two-photon-generated photoacid initiator with symmetric structural character of D-Ï€-D have been designed and successfully synthesized, which can be divided into carbazole, triphenylamine and phenothiazine derivatives in terms of their central heterocycle. The target molecules were fully characterized by elemental analyses, IR, 1H-NMR, MS and ESIMS. A typical structure for the compounds was analyzed by single crystal X-ray diffraction method. The results of nonlinear optical determination revealed that the compounds exhibit strong TPA effect and can be regarded as efficient two-photon photopolymerization initiators in application for three-dimensional microstructures technology. The thesis includes five chapters:1. The recent developments in the research for TPA materials and two-photon photopolymerization initiators are reviewed based on reading of a great deal of related literatures.2. Eight novel symmetric multibranched compounds were successfully synthesized in high yield by Heck reaction, which were fully characterized by elemental analyses, IR, 1H-NMR, MS and ESIMS. Single crystals of the typical compound were obtained by solvent evaporation and determined by single X-ray diffraction analysis. Its structural characters were studied in detail.3. The linear and nonlinear optical properties of the compounds in deferent solution were determined including solvent effects. Form the experiment results, it can be drawn that dibranched or tribranched compounds above hold good single- and two-photon fluorescence properties.4. The three-dimension microstructures were successfully obtained by two-photon polymerization of an acrylic ester oligomer using the newcompounds as initiators under the excitation of fs laser, the wavelength is about twice as much as the maximal absorption.5. Two novel two-photon-generated photoacid initiators derived from phenothiazine were synthesized in high yield by Wittig reaction, which were characterized by IR and ESIMS.