Study on the relationship between structure and fluorescence properties of anthracene derivatives

• The crystal structures of five anthracene derivatives have been reported, and Hirshfeld surface analysis has also been done. • Non-fluorescent compounds tend to become strongly fluorescent when exposed to air under acidic conditions. • The compounds reported here have potential application value. • The synthetic method reported here is simple and promising in the future. We have designed and synthesized five anthracene derivatives using quinoa perch ether and 2-acetaldehyde pyridine or 4-acetaldehyde pyridine as raw material. Five compounds are 2-(9,10- dihydro-2,3,6,7-tetramethoxy-10-(pyridin-2-yl) anthracen-9- yl)pyridine ( 1 ), 2-(2,3,6, 7-tetramethoxy-10-(pyridin-2-yl)anthracen-9-yl) pyridine ( 2 ), 4-(9,10-dihydro-2,3,6,7 -tetramethoxy-10-(pyridin-4-yl) anthracen-9-yl) pyridine ( 3 ), 4-(2,3,6,7-tetramethoxy- 10-(pyridin-4-yl)anthracen-9-yl) pyridine ( 4 ), and 4-(2,3,6,7- tetramethoxy-10-(pyridine-4-yl)anthracen-9-yl) pyridine nitrate ( 5 ), respectively. Their single crystals were obtained and determined by X-ray diffraction analysis, and their Hirshfeld surface analysis has also been done. Different compounds with different structures can be obtained from the same raw material by changing the reaction conditions and the concentration of acid. Their fluorescence properties also changed greatly. Structural analysis showed that compounds ( 1 ) and ( 3 ) were chiral compounds. Both C9, C18 in compound ( 1 ) and C6, C15 in compound ( 3 ) are chiral carbon atoms. However, when compounds ( 1 ) and ( 3 ) lose their two protons and become compounds ( 2 ) and ( 4 ), respectively, which can form an π-conjugated system, there are no chiral carbon atoms and have fluorescence. It lays a foundation for the potential applications of these compounds in the future.