A　purely　organic　compound　2-(9H-carbazol-9-yl)-3-(2-(2,4,5-tri-(9H-carbazol-9-yl)-3,6-dicyanophenoxy)phenoxy)dibenzo[b,e][1,4]dioxine-1,4-dicarbonitrile,　C76H40N8O4,　was　synthesized　and　characterized　by　NMR,　UV-Vis,　photoluminescence　and　X-ray　single-crystal　structure　analysis.　The　compound　crystallizes　in　monoclinic　system,　space　group　P21/n　with　a　=　11.6537(3),　b　=　34.9738(8),　c　=　15.5053(3)　Å,　β　=101.992(2)°,　V　=　6181.6(2)　Å3,　Z　=　4,　Mr　=　1129.18　g/mol,　Dc　=　1.396　g/cm3,　F(000)　=　2672,　μ　=　2.239　mm–1,　GOOF　=　1.019,　the　final　R　=　0.0577　and　wR　=　0.1559　for　11925　observed　reflections　with　I　>　2σ(I).　The　UV-vis　absorption　and　fluorescence　of　the　compound　were　discussed.　The　compound　exhibits　yellow-green　luminescence　with　maximum　emission　peak　at　538　nm,　and　quantum　yields　of　ф　=　0.25　and　0.48　in　air-equilibrated　and　degassed　toluene　at　room　temperature.　Transient　decay　spectral　studies　show　that　compound　1　displays　two　component　decay　fashions　with　a　short　decay　lifetime　of　23　ns　for　the　prompt　fluoresce　and　a　long　decay　lifetime　of　3.8　μs　for　thermally　activated　delayed　fluorescence.　In　air-equilibrated　toluene,　only　a　short　decay　lifetime　of　17　ns　was　observed.　The　experimental　and　computational　results　show　that　the　emission　of　the　compound　originates　from　the　CT　excited　states.　©　2018　Fujian　Institute　of　Research　of　the　Structure　of　Matter.　All　Rights　Reserved.