Pyridyl substitution at the 2,6-positions of anthracene toward crystal polymorphs with distinct optical characteristics†
Abstract
For molecular materials, the packing motif plays a pivotal role in determining the optoelectronic characteristics, and it can be tailored via altering not only the molecular structure but also the crystal polymorph. However, it remains a long-standing difficulty for one molecular material to achieve both herringbone packing and 1D slipped stacking, shielding the relationship between the two classic motifs and the functional properties. Herein, we demonstrate that pyridyl substitution at the 2,6-positions of anthracene opens up the possibility of crystal polymorphism from herringbone packing to 1D slipped stacking. The two crystal polymorphs show distinct crystal morphologies, emission spectra, optical anisotropy, and waveguiding properties, shedding light on the relationship between the packing arrangement and optical characteristics based on the same molecular structure.