Polymorphism-Dependent Emission of Nonaromatic Luminophores

Recently, nonconventional luminophores have received increasing attention, owing to their fundamental importance, advantages in outstanding biocompatibility, easy preparation, environmental friendliness and potential applications in sensing, imaging, encryption, etc. In order to provide more information about relationship among molecular conformation, molecular packing and emission, and moreover, to guide the design of nonconventional luminophores, molecules with definite structures and explicit molecular packing are highly desired. In this contribution, we report two nonconventional luminophores, namely F-MA and F-MI, consisting of carbonyls (C=O), electron-rich heteroatoms (O/N), and unsaturated C=C subgroups. They are nonluminous in dilute solutions while being emissive in concentrated ones. Furthermore, through crystallization in different solvents, polymorphs of both compounds with various emission colors along with distinct room temperature phosphorescence (RTP) are successfully obtained. Under 312 nm U