Formation and Growth of Molecular Nanocrystals Probed by their Optical Properties

A red fluorescent zwitterionic molecule based on the diaminodicyanoquinodimethane framework is synthesized and structurally characterized. Formation of nanocrystals of this molecule through the reprecipitation protocol is followed by examining the optical absorption and emission. Computational modeling based on molecular and crystal structures provides insight into the assembly of molecules during colloid formation. Molecular nano/microcrystals of increasing size are fabricated through a digestion procedure, and the size-dependent optical properties are investigated by spectroscopy and microscopy. Utility of polymer wrapping to arrest the growth of these crystals is described.