MEI Qun-bo, DU Nai-ying, LIANG Li-yan, LÜ Man-geng. Synthesis and Characterization of High Molecular Weight Polymers Containing 8-Hydroxyquinoline Lithium Complexes[J]. Chinese Journal of Luminescence, 2006,27(6): 1000-1006
MEI Qun-bo, DU Nai-ying, LIANG Li-yan, LÜ Man-geng. Synthesis and Characterization of High Molecular Weight Polymers Containing 8-Hydroxyquinoline Lithium Complexes[J]. Chinese Journal of Luminescence, 2006,27(6): 1000-1006DOI:
Synthesis and Characterization of High Molecular Weight Polymers Containing 8-Hydroxyquinoline Lithium Complexes
The electroluminescent polymer-metal complexes constitute an important class of functional materials and have found widespread use in the polymer light-emitting diodes(PLED). In recent years
they have become a new and fascinating area of research and attracted great interest as future flat-panel displays in the global and obtained the prodigious progress. As we known
there are two traditional approaches to obtain electroluminesent metalloquinolate thin films: vapor deposition in vacuum from the small molecules and filmcasting from the solution of the metalloquinolate-doped polymers. However
morphological changes during thermal treatments lead to partial crystallization of layered structure that ultimately results in device failure. Although the metalloquinolate-doped polymers can overcome these problems
current limitations are their heterostructures
which will affect device efficiencies and lifetimes. The metalloquinolate-contianing polymers that the covalent bond formatted between 8-hydroxyquinoline metal complexes with polymers for electroluminescence applications in PLEDshould combine the fluorescent properties of metalloquinolate and the processability of polymer. Anew method to synthesize 8-hydroxyquinoline lithium (Liq)-containing polymers were reported. Aseries of model polymers containing 8-hydroxyquinoline ligands were obtained by free-radical copolymerization with methyl methacrylate (MMA)
styrene(S). High molecular weight polymer-lithium complexes were simply prepared by coordinating reaction of model polymers with lithium hydroxide. It is linear without cross-linking and can be dissolved easily in the common solvents
such as tetrahydrofuran(THF)
and N
N′-dimethyl formamide(DMF). The method is fit to synthesize most of 8-hydroxyquinoline metal chelates-containing polymers by change the polymer chains or metal central ion. Their structures and performances were confirmed by NMR
FTIR
ultraviolet-visible absorption
photoluminescence spectrum
DSC
TGAand gel permeation chromatography analysis. Ultraviolet-visible absorption and PL emission spectra are consistent with that of small molecular weight Liq complexes that show the luminescence of polymers is nothing to do with polymer segments
but due to containing Liq functional group. The solvents
such as THF
affected the conjugated electrons in quinolinolate group and made the spectra of polymers a red shift obviously.