Synthesis And Properties Of Functional Conjugated Luminescent Polymers

Conjugated polymers (CPs) are the polymers based on π-conjugated organic molecules and chain backbone structures and the delocalization of the electrons facilitates the electronic and energy migration along the whole polymer backbone. These functional polymers can be used to prepare fluorescence chemosensors, electroluminescent devices, nonlinear optical materials and dye-sensitized solar cells etc.This dissertation was divided into two parts. In the first section, the studies focused on the design, synthesis and fluorescence study of chiral β-ketoiminate-based newly boron hybrid conjugate polymer. And in the second part, the paper mainly studied on the design, synthesis and properties of conjugated polymers based on 2,4,6-triphenylpyridine.1. Fluorescence Study of Chiral P-ketoiminate-based Newly Synthesized Boron Hybrid PolymersTwo novel chiral β-ketoiminate-based boron hybrid polymers P-1 and P-2 were synthesized by chiral β-ketoiminate-based boron hybrid complex (M-1) with 1,4-dioctyl-2,5-diethynylbenzene (M-2) and 3,6-diethynyl-9-octyl-9H-carbazole (M-3) via a Pd-catalyzed Sonogashira coupling reaction, respectively. The resulting polymers P-1 and P-2 show strong fluorescence emission centered at 525 nm and 534 nm with large Stokes shifts and high quantum yields. Most importantly, compared with the circularly polarized luminescence (CPL) dissymmetry factor (glum=+0.042) of chiral small model molecule, P-1 and P-2 can exhibit large glum as high as +0.105 and +0.349 in CH2Cl2 solution, which can be attributed to the amplification effect of CPL arising from conjugated polymer structure.2. Synthesis and Fluorescence Properties of 2,4,6-triphenylpyridine-based Conjugated Luminescent PolymersThree novel 2,4,6-triphenylpyridine-based conjugated polymers could be synthesized via palladium-catalyzed Sonogashira coupling reaction. Compared with model compounds, the resulting polymers show strong fluorescence emission with large redshift and exhibit high fluorescent quantum yield from 0.26 to 0.43. Density functional theory (DFT) calculations are performed on three polymers repeat units, and HOMO and LUMO energy levels of the conjugated polymers are estimated. The band gap (Eg) of cyclic voltammetry (CV) is conformed to Eg of DFT, and the order is the same.