Organic Crystal Growth: Directly from Amorphous Solid Powder to Single Crystals

Preparation of organic crystals mainly depends on solution‐deposition, sublimation, and melt‐deposition techniques. Solid‐state growth methods are generally not suitable for organic crystal growth due to the unprocurable mass transfer. Herein, we report two pyridine‐substituted fluorenone compounds with extraordinary crystal‐growth capacity, and these compounds can directly and quickly form single crystals from their amorphous solid powder by heating under antisolvent‐assistance conditions. The novel experimental phenomenon and crystal growth mechanism were investigated in depth. The results indicate that multiple intermolecular hydrogen‐bonding sites and planar aromatic structure (prone to π‐π interactions) of these molecules dominate the mass transfer during crystal growth by providing enough energy. This discovery enhances our knowledge of solid‐state methods for single‐crystal growth. Herein, we present a new discovery of organic crystal growth method from amorphous solid powder to single crystal directly by heating under antisolvent‐assistance conditions. The mechanism studies reveal that multiple intermolecular hydrogen bonds and π‐π interactions dominate the mass transfer of crystal growth when enough energy is provided.