Phenothiazine-S,S-dioxide- and fluorene-based light-emitting polymers: Introduction of e−-deficient S,S-dioxide into e−-rich phenothiazine (pages 1236–1246)
Jonghee Lee, Jeong-Ik Lee, Moo-Jin Park, Young Kwan Jung, Nam Sung Cho, Hoon Je Cho, Do-Hoon Hwang, Sang-Kyu Lee, Jong-Hwa Park, Jiwon Hong, Hye Yong Chu and Hong-Ku Shim
Article first published online: 16 FEB 2007 | DOI: 10.1002/pola.21890
Poly(10-hexyl-phenothiazine-S,S-dioxide-3,7-diyl) and poly (9, 9′-dioctyl-fluorene-2,7-diyl-alt-10-hexyl-3,7-phenothiazine-S,S-dioxide) (PFPTZ-SS) copolymers were successfully synthesized through Yamamoto polymerization and Suzuki polymerization. The inclusion of SO2 moieties in the phenothiazine and fluorene copolymers changed the frontier orbital energy levels and presented an effective way of increasing the electron affinity of the copolymers. These phenothiazine-S,S-dioxide-based polymers showed higher glass transition temperatures than pristine polyfluorene and exhibited strong florescence with bright blue emissions in the solid state. Additionally, we provide an explanation for the higher electroluminescence properties of PFPTZ-SS in light-emitting diode devices. These findings thus establish a strategy for improving the light-emitting properties of polyfluorene derivatives, which may eventually prove useful in polymeric light-emitting diode device applications.