Molecular Design, Synthesis, Characterization And Property Studies Of Organic-lnorganic Hybrid Pyridinium

The hybrid of organic-inorganic materials at the molecular level can create a chance to optimize the properties of function groups. In the thesis we introduced a large conjugated group into styrene pyridinium framework and synthesized six novel cations, and the structure and the properties were investigated by varying different anions. Among these thirty newly synthesized compounds, three crystal structures of corresponding compounds were determined by single crystal X-ray diffraction.Three chapters are comprised in the thesis:The first chapter: We found that the combination of organic and inorganic ions makes functional properties well via strong interaction of cations and anions; styrene pyridinium have so various structures as to be designed and tailored easily.The second chapter: The part introduces synthesis methods of a series of novel compounds, which were fully characterized by electron spray mass spectra, IR elemental analysis and TGA. Three of them were analyzed by single crystal structures determination. The functional properties of the new compounds were explained based on their structure.The last chapter: We have systematically studied the optical properties of the series of compounds. The part of linear optical can be divided into electron spectra and one-photon fluorescence spectra. In electron spectra, introducing of 9-methyanthracene makes styrene give rise to red shift. Solvent effects of new compounds were systematically studied and quantum yields were calculated by one-photon fluorescence spectra. We found that the quantum yield of these compounds are higher than that of DAMS* pyridinium(N-methylpyridinium). In nonlinear optical studies, we calculated two-photon absorption cross-sections by determining Z-scan. We obtained up-conversion lasing efficiency by determining two-photon up-conversion lasing. At the end we concluded that the new compounds can produce strong two-photon fluorescence and high up-conversion lasing efficiency even at low concentration. At the same time an interesting phenomenon was found that the hybrids show stronger larger two-photon absorption cross-sections when their anions have non-linear properties.In a word, we have obtained a series of compounds with potential applications in lasing materials by employing molecular design and organic-inorganic hybrid strategy. The study of organic-inorganic hybrid materials at molecular level may provide some important information on the structure-property relationship, which may in turn guide exploring in up-conversion lasing materials researches.