Creation of Luminescent Organic Crystal Utilizing Crystal-phase Composite Interactions

Abstract

Luminescence behavior of crystalline diaroylmethanatoboron difluoride (1BF₂ ) were studied. Derivatives of 1b-gBF₂ with various alkyl substituents in size and geometry show remarkably different fluorescence in the crystalline state, as a result of different intermolecular interactions. The behavior is explained by intermolecular interaction taking place in multiple molecules, referred to as “excited multimer”. It is also revealed that isopropyl derivative (1fBF₂ ) and iodine-substituted derivative 1iBF₂ show white-light emission and intense room temperature phosphorescence, respectively. The luminescent characteristics of crystals of 1BF₂ are controlled by the crystal-phase composite interaction.