Synthesis And Properties Of 3,3'-bithiophene Derivatives With High Fluorescence Emission

Thiophene organic conjugated fluorescent materials have the advantages of stable properties,easy structure modification,easy processing,excellent optoelectronic performance,environmental friendliness,and good biocompatibility.They are widely used in organic photovoltaic materials such as organic photovoltaic cells,sensors,organic photosensitized batteries Manufacturing and medical imaging,ion probes and other fields.Therefore,it has attracted extensive research in academia.At present,researches on thiophene organic conjugated fluorescent materials with high fluorescence emission,good environmental stability,strong electron affinity,etc.have been relatively rich,but most of them are concentrated on thiophene organic macromolecules or polymers containing thiophene units.Therefore,the design and preparation of thiophene organic conjugated small molecule fluorescent materials with novel structure and excellent comprehensive performance has become one of the research hotspots in the field of fluorescent materials.In this paper,3,3'-bidithiophene is used as the mother core to design and synthesize two types of thiophene functional organic small molecule derivatives with A-?-A or D-?-D structure 4,4'-distyryl-3,3'-bidithiophene derivatives(IV-DSBTs)and 5,5'-distyryl-3,3'-bidithiophene derivatives(V-DSBTs).And systematic research on its fluorescence emission,electrochemistry,ultraviolet absorption,thermodynamic stability,theoretical calculation and crystal structure,etc.,and selected some compounds with excellent performance.For its solvochromism,thermochromism(the effect of temperature on its emission spectrum in dilute solution and solid powder),aggregation-induced luminescence(AIE)effect,cyclic voltammetry(CV)curve,thermal stability test.Studies have shown that all compounds exhibit excellent fluorescence emission properties.Among them,IV-DSBTs-2 and V-DSBTs-2 have special optical properties,which show obvious solvochromic and thermochromic properties in dilute chloroform solution,and also have high fluorescence emission ability in the state of thin film.Cyclic voltammetry and thermogravimetric analysis show that the compound has excellent electron affinity and thermal stability.In addition,the single crystal X-ray diffraction provides a deeper understanding of the spatial configuration and luminescence mechanism of 3,3'-bidithiophenemolecules.Finally,the use of theoretical calculations on structure,frontier molecular orbitals,and electronic transitions provides a theoretical basis for the observed structure-function relationship.Therefore,3,3'-bidithiophene derivatives,especially the two compounds IV-DSBTs-2 and V-DSBTs-2,have great potential value in the field of optoelectronic materials.