Design, Synthesis, Crystal Structures And Nonlinear Optical Properties Of Hybrid Materials From Pyridine Derivatives

Pyridinium derivatives as a kind of nonlinear optical materials have attracted considerable attention in the field of optoelectronic materials due to their flexible molecular design, various assembly formations and strong nonlinear optical response. In this dissertation, three different series of pyridinium materials were designed and synthesized based on the comprehensive with recent developing of research on pyridinium nonlinear optical materilas. The photophysicall properties were systematically investigated, and the relationships between properties and structure of the compounds were studied deeply. The main contents are concluded as follows:1. Synthesis and nonlinear optical properties of the tetraphenylborate pyridinium compounds(1) In this dissertation, four D-π-A configurational compounds (BL1, BL2, BL3and BL4) have been synthesized using pyridinium-based chromophores and tetraphenylborate as anions, by inducing the different donor groups.(2) The crystal structures of two compounds were solved; the results show that there is a highly π-electron delocalized system in the molecules.(3) The influences on linear and nonlinear optical properties with different donor groups have been thoroughly explored by the experimental data and theoretical calculations, and rationally explanations were given. The results show that the nonlinear optical propertities have been improved by introducing the flexible chains.(4) The third-order nonlinear optical properties of BL4were systematically studied by Z-scan method, it exhibits peak intense two-photon fluorescence emission when excited at the narrow wavelength range of a near-infrared pulse laser and possesses very large values of the real part of the cubic hyperpolarizability χ(3), a remarkably low T factor (<<1).2. Two-photon biocompatible materials:a new series of sulfonated pyridinium derivatives for biological imaging application(1) In this dissertation, a new series of D-π-A type two-photon absorption (2PA) water-soluble salts (SL1, SL2, SL3and SL4) based on pyridinium have been synthesized and fully characterized.(2) The crystal structures of two compounds SL1and SL2were solved; the ethyl units play an important role in twisting the main structure in comparison with SL1, because the ethyl phenylamine segment, compared to methyl phenylamine group, has much more steric hindrance and hence might more powerfully prevent unfavorable π-π stacking interactions between the molecules.(3) Photophysical properties of them have been systematically investigated based on both experimentally and theoretically. The influences on optical properties with different donor groups have been thoroughly explored by the experimental data and theoretical calculations, and rationally explanations were given.(4) SL4displays2PA activity when dissolved in water; its anti-neoplastic activity was tested by MTT method. Moreover, we also demonstrated that SL4offers a potential application in two-photon fluorescence imaging which is capable of detecting the caryon section in HepG2cells due to its excellent biocompatibility and low toxicity.3. Synthesis, crystal structure and nonlinear optical preliminary exploration of rare earth complexes of pyridinium(1) In this dissertation, twelve kinds of pyridinium rare earth complexes by introducing six different rare earth metal ions were designed and synthesized based on two-photon activity pyridinium.(2) The crystal structures of ten kinds of complexes were solved. The results show that all complexes are structurally similar, the crystal systems are monoclinic with space group P21/n except compound7which belongs to P21/c. In addition, the crystal structures of them show that they are formed with pyridinium cation and [Ln(TTA)4]-moieties, Ln(III) ion is surrounded by four2-thenoyltrifluoroacetonate ligands. The coordination number of the Ln(III) ion is eight, and the coordination polyhedron can be described as a distorted square antiprism.(3) We studied the optical properties of6and12and found that compound12can sensitized to rare earth luminescent, it exhibited nonlinear optical activity when excited by femtosecond pulse laser in the wavelength710nm.