Supramolecular self-assembly structures and properties of zwitterionic squaraine molecules

To further investigate the influence of H-bond combining with pi-pi stack interaction on the optical performances, a few rigid zwitterionic squaraine molecules, with different terminal H-bond recognition abilities, are identified and designed. They can controllably construct a series of supramolecular self-assemblies with different morphologies and dimensions via a simple solution-based self-assembly method under mild conditions. The morphologies, synergetic reinforcing effect, and optical-thermal properties are investigated and confirmed by both theoretical and experimental methods. The results indicate that the morphologies of the resultant self-assemblies can be effectively controlled by rational molecular design, whose absorption and emission spectra and thermal stabilities accordingly change with the alteration of zwitterionic squaraine molecular structures.