Abstract:
The crystal structures of three bis-pyridyl-alkyl-di-imines are studied. The non-covalent interactions lead to the packing of the crystals of the compounds in such a way that crystallization induced emission (CIE) is observed for bis-pyridyl-ethyl-di-imine and bis-pyridyl-butyl-di-imine, while for bis-pyridyl-di-imines, with no alkyl spacer, the luminescence is absent in the solid state. The enhanced emission in the solid state is attributed to the collective effects of planarization and the specific arrangement of molecules.