The solvent-induced morphological changes of organic microstructural materials: Morphology-sensitive photophysical properties

The research reported herein demonstrates the great effects of solvent type (protic/aprotic)/polarity on morphologies of boron-difluoride complex microstructural materials. We found that the hydrogen bonding interaction between protic solvent (water or ethanol) and boron-difluoride complex could subtly tune the anisotropic growth to give sheetlike morphologies. However, the aprotic dipole solvent (acetonitrile or acetone) mainly induces unusual hexangular prismlike or cubelike morphologies. It is interestingly found that the solvent polarity also has important influence on morphologies. Compared to prismlike or cubelike morphologies, microsheet morphologies reveal enhanced luminescent emission and near-infrared absorption, which should be attributed to morphological anisotropy, demonstrating morphology-sensitive photophysical properties. This work exemplifies that solvent type (protic/aprotic)/polarity can significantly tune the morphologies and properties of organic micro/nanomaterials.