Comparative studies of photophysics and exciton dynamics of different diphenylanthracene (DPA) nanoaggregates

The systematic change in phenyl-anthracene dihedral angle and its effect on the systematic change upon the photophysical properties of different DPA nanoaggregates. [Display omitted] •Alteration in phenyl substitute positions in DPA derivatives results different phenyl-anthracene dihedral angle.•Different dihedral angle causes difference in intermolecular interactions, confirmed by absorption band shift due to aggregation.•Different molecular packing of different DPAs also cause change in exciton-excimer photophysics.•Singlet exciton diffusion become faster as the DPA achieved more planar molecular structure. Diphenyl derivatives of anthracene (DPA) have attracted extensive research interest in recent time due to their prospective application in organic light emitting diode (OLED) and other optoelectronic devices. Systematic investigation on the influence of phenyl substitution on optical properties of anthracene is lacking, even though the positions of phenyl substitution in the anthracene moiety are expected to alter the molecular interaction and molecular packing in solid state, having impact on photophysics and excitonic properties of these materials. In present work, we have investigated photophysics of three DPA derivatives namely, 2,6-diphenylanthracene, 1,8-diphenylanthracene and 9,10-diphenylanthracene in their nanoaggregate form. Owing to different positions and different dihedral angles (relative to anthracene plane) of the phenyl substituents, crystalline packing and intermolecular interaction are significantly modulated, resulting in diverse photophysical properties in nanoaggregated state. We have discussed the role of phenyl substituents on the interplay of exciton - excimer photophysics and exciton diffusion properties of these anthracene derivatives in relation to their potential application in OLED and photovoltaic devices.