Synthesis of 1,3-Diphenyl-6-alkyl/aryl-Substituted Fulvene Chromophores: Observation of π–π Interactions in a 6-Pyrene-Substituted 1,3-Diphenylfulvene

The synthesis, structural, and electronic properties of nine 1,3-diphenyl-6-alkyl/aryl substituted pentafulvenes were studied. Pyrene ring π–π interactions were revealed from analysis of the experimental crystal packing of 1,3-diphenyl-6-(1-pyrene)­fulvene and supporting DFT calculations. Photophysical properties derived from UV–vis and fluorescence emission measurements demonstrated tunable and low HOMO–LUMO band gaps for the series. The presented results point to a model synthetic approach for incorporation of extended π systems and donor-π-acceptor groups for fulvene-based electronic materials.