Several Molecular Cocrystal Materials: Synthesis And Optical Properties

Nowadays, molecular photofunctional materials have gained great attention because of their application in the fields of energy, illumination, information storage, sensor, solid-state laser and detection. A lot of photo-functional species have been synthesized to meet the increasing needs. However, how to construct new high-performance photofunctional materials is still a major challenge for us to promote the technological progress. Multi-components molecular solids (such as cocrystals) are new types of materials which can be synthesized based on two or more available molecule-based compounds. Cocrystalization is a new way for us to tune the photo-related properties of the classic materials. Moreover, it allows us to design new solid state structures and to reveal the relationship between structure and properties of the materials.Based on the expectation that the formation of multi-component materials and molecular self-assembly can alternate the molecular stacking in the solid state, which can further influence their optical/electronic properties, herein, we have selected several co-formers (such as 1,4-dibromotetrafluorobenzene, chloranilic acid, tetrafluoroterephthalic acid, hydroquinone and 4,4'-dibromo-2,2',3,3',5,5',6,6'-octafluoro-1,1'-biphenyl) which can potentially assembled with the ?-conjugated molecule material through intermolecular interactions (such as halogen-/hydrogen-bonds and ?…? interaction). The single crystal X-ray diffraction has been taken to reveal the molecule stacking type of the cocrystals. In addition, periodic density functional theoretical (DFT) calculations were performed to explore detained electronic structures of the pristine material and cocrystals, to show the differences in energy level structures and orbital distributions of the pristine ones and multi-component fluorophores. At the end, we have detected the possibility in practical applications (such as multiple-stimuli responsive luminescence, electrochemiluminescence-based nitrite detection and up-conversion fluorescence) for these new cocrystals.