Preparation Of Polystyrene With Ligand On Its Side Chain And Researching On Photoluminescence Character Of Polystyrene-metal Complex

Polymer-metal complexes is a high performance luminescence materials, The complex possesses the excellent photoluminescence and electroluminescence properties, and easy processing characteristics of polymers, Polymer-metal complexes is a investigative hotspot in luminescence materials. In this paper, via bond small molecul ligands on side chains of polystyrene, two species of polymer-metal complexes were prepared, and its fluorescence properties were mainly investigated. For polymer-metal complexes application provide an important reference in the area of organic photoelectric materials.Polystyrene on whose side chains salicylic acid (ASA) ligands were bond were prepared with chloromethylated polystyrene (CMPS) as starting substance via two-step polymer reactions, phase-transfer catalytic esterification and Schiff c in a homogeneous system, resulting in the functional polymer SAPS. The chemical structure of the product were characterized by infrerad spectroscopy and 1^H-NMR spectroscopy. The effects of main factors on phase-transfer catalytic phase-transfer catalytic were investigated emphatically.The experimental results show that with the phase-transfer catalysis action of quaternary ammonium salts, the esterification reaction between the chloromethyl groups of CMPS in organic phase and sodium glyoxylate in water can be carried out effectively, forming aldehyde (AL) group-functionalization polystyrene ALPS. Different factors such as reaction temperature, the structure of the phase-transfer catalysts, the polarity of the solvents, and the volume ratio of organic phase to water phase affect the phase-transfer catalytic reaction greatly. The optimal reaction conditions are as follows: with reaction temperature at 70℃, with tetrabutylammonium bromide as catalyst, with chloroform as solvent and adapting an O/W ratio of 1:2. In a homogeneous system, the Schiff reaction between the modified polymer ALPS and 5-aminosalicylic acid is easy to be conducted, forming the functional polymer SAPS with aldehyde group was conversioned 80%.The macromolecules SAPS were allowed to coordinate with rare earth Eu(â…¢) ions, and the polymer-rare earth complex SAPS-Eu(â…¢) was prepared. The complex was characterized, and its fluorescence properties were mainly investigated. The experimental results show that on the one hand the complex SAPS-Eu(â…¢) has the chemical stability because of that the ligand SA is a bidentate chelate group, and more importantly, the ligand SA chemically attaching onto polystyrene possesses strong sensibilization for the fluorescence emission of Eu³⁺ ion and it can make the complex SAPS-Eu(â…¢) to produce obvious antenna effect. In the diluted solution of functional polymer SAPS, the apparent saturated coordination number of the ligand SA for Eu³⁺ ion is equal to 10, and at this point, the complex SAPS-Eu(â…¢) has the strongest fluorescence emission. Here, if small molecular ligand 1,10-phenanthroline (phen) as the second ligand is added into the solution, a complementary coordination process will be produced, resulting in the enhancement of the fluorescence intensity. Only 1 mole phen is added according to the ratio of phen to Eu(â…¢), the coordination of Eu³⁺ ion with the ligands can reached completely saturation. By the synergism coordination action of the first and second ligands, the fluorescence intensity of the complex can increase up to 3 times the original.5-chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the reaction HQ and chloromethylation reagent 1,4-bichloromethoxy-butane (BCMB). The Friedel- Crafts alkylation reaction was carried out between CHQ and polystyrene (PS), and HQ was bound onto the side chains of PS, obtaining the modified polystyrene HQ-PS. And then, the coordination reaction between HQ-PS and 8-hydroxyquinoline aluminum complex Alq₂ that have two HQ ligands was conducted, and the luminous material Alq₃-PS that contains 8-hydroxyquinoline aluminum complex Alq₃ was achieved, namely the polymeric Alq₃ was prepared. In order to characterize the chemical structure and property of Alq₃-PS, several measurements were performed such as FTIR, 1^H-NMR, UV/Vis absorption and thermogravimetric Analysis (TG), and its luminous performance was investigated. The effects of the main factors on the Friedel-Crafts alkylation reaction were investigated, and the reaction conditions were optimized. The experimental results show that the Friedel-Crafts alkylation reaction between PS and CHQ can proceed successfully, and the suitable reaction conditions are as follows: a temperature of 70℃, with N,N-dimethyl formamide (DMF) as solvent and using SnCl₄ as Lewis catalyst. The Alq₃-containing polystyrene, Alq₃-PS, possesses the fluorescence-emission spectrum of Alq₃, and has higher thermostability than polystyrene.