Synthesis and characterization of fluorene-based electroluminescent polymers containing silyl groups

Abstract

Two types of fluorene-based copolymers, poly(9,9'-di-n-hexyl-2,7-fluorenediylethynylene-alt-9-trimethylsilyl-2,7-fluoreneethynylene[P-1], poly(9,9'-di-n-hexyl-2,7-fluorenediylethynylene-alt-9,9'-bis-trimethylsilyl-2,7-fluoreneethynylene[P-2] were synthesized by employing palladium catalyzed polycondensation. Resulting polymers showed a good solubility in various organic solvents such as THF, chloroform, dioxane etc. and could be easily spin-coated onto an ITO glass plate to make a fine thin film. Characterization of these polymers includes FT-IR, UV-vis., H-1 and C-13-NMR, was conducted. Thermal properties were also investigated by DSC and TGA as well as molecular weight studies. The present polymers exhibited emission of blue-white color. The photoluminescence (PL) spectrum of the polymers showed two peaks at 490 and 540 nm and it was found that electroluminescence (EL) spectra of the polymer [P-2] was very similar to its PL spectrum.