Tunable solid-state fluorescence emission and red upconversion luminescence of novel anthracene-based fluorophores

Novel, tunable solid-state emitters based on anthracene groups were synthesised and characterised by spectroscopy and elemental analysis. Their solid-state photoluminescence properties were studied. These fluorophores display interesting solid-state emission properties with an emission at wavelengths ranging from 550 to 650nm when excited by a 325nm heliumcadmium laser at room temperature. In particular, among them, 1,6-di(9-anthryl)hexa-1,5-diene-3,4-dione, 2-[4-(2-benzoxazolyl)phenyl]-4,5-bis[2-(9-anthryl)vinyl]-1H-imidazole and 2,3-bis[2-(9-anthryl)vinyl]quinoxaline show red, yellow and green emission, respectively, at 650, 584 and 550nm. The results demonstrated that the luminescent colours can be tuned from red to yellow and green by simply varying molecular structure. Besides, 1,6-di(9-anthryl)hexa-1,5-diene-3,4-dione also exhibited an upconverted red fluorescent emission peak at around 675nm under femtosecond excitation at 800nm.