title: π-Extended indenofluorenes.
abstract: A series of π-extended aromatic indenofluorene (IF) analogues with naphthalene and anthracene cores have been synthesized through acid-catalyzed intramolecular cyclization. The regioselectivity of the reaction is controlled by a combination of steric and electronic factors and in some cases several possible regioisomers have resulted from the same precursor. The effects of ring connectivity on the optoelectronic properties were investigated by DFT calculations, absorption/emission spectroscopy, cyclic voltammetry, and spectroelectrochemical studies. All regioisomers exhibited a redshift of their absorption/emission bands relative to the parent IF analogues, but the magnitude of this shift and other optoelectronic properties (luminescence quantum yield, etc.) depends on the ring connectivity in a less obvious manner.
authors.affiliation: Department of Chemistry and Centre for Self-Assembled, Chemical Structures, McGill University, Montreal, QC H3A 0B8 (Canada).
authors.forename: M Rajeswara
authors.initials: MR
authors.lastname: Rao
authors.forename: Antonin
authors.initials: A
authors.lastname: Desmecht
authors.forename: Dmitrii F
authors.initials: DF
authors.lastname: Perepichka
keywords: acenes; conjugation; fused-ring systems; indenofluorenes; organic electronics