Poly(indenofluorene)s (PIF) — Novel conjugated pojyhydrocarbon polymers

We are describing the synthesis of a novel class of hydrocarbon polymers, poly(indenofluorene)s PIF, composed of 3,9-di-t-butylindeno[l,2-b]fluorene- (2) or 3,7-di-t-butylindeno[2,1-b]fluorene (7) building blocks. The polymers, with high degrees of polymerization (DP: > 20), were generated by reductive coupling of the tetrachloro-indenofluorene monomers 5 and 6 with low valent transition metal reagents as dehalogenating agents. PIF 2 exhibits a widely red shifted longest wavelength absorption maximum (λmax: ca. 800 nm, 1,55 eV). We have also generated diketo-terminated oligomeric model compounds 9. The oligomers 9 are suitable models for an investigation of the electronic properties of the corresponding polymer PIF 2.