International Journal of Organic Chemistry

Naofumi Naga ¹, Nanae Tagaya ¹, Haruhiko Tomoda ¹

Affiliations
1 Department of Applied Chemistry, Materials Science Course, College of Engineering, Shibaura Institute of Technology, Tokyo, JP

Abstract

Alternating copolymerization of 9,9-dihexyl-2,7-dibromofluorene, N-hexyl-2,7-dibromocarbazole (HCz) with diethynyldimethylsilane, diethynyldiphenylsilane, has been investigated using Sonogashira coupling reaction. Photophysical properties of the resulting copolymers were investigated with UV-Vis absorption and photoluminescence spectroscopy. All the copolymers in chloroform solution showed absorption peaks at 270 - 280 nm with shoulder peaks at around 380 nm derived from π-π^* transition or intra-molecular charge transfer through σ-π moiety, respectively. The chloroform solutions of the copolymers showed broad emission peaks at 415 - 425 nm. The emission wave lengths of the copolymers in the solid state (cast film) detected at 360 - 385 nm were remarkably blue-shifted in comparison with those in the chloroform solutions. Hydrosilylation reaction of the copolymers with 1,4-bis(dimethylsilyl)benzene yielded networked copolymers soluble in chloroform, indicating formation of branching polymers. The chloroform solutions of the HCz-based networked copolymers showed bimodal emission derived from new highly energy states in the σ-π conjugation.

Keywords

Fluorene, Carbazole, Alternating Copolymer, Si-Ethynylene, Photophysical Property, Network Polymer.

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