Colour-tuneable solid-state fluorescence of crystalline powders formed from push-pull substituted 2,5-diphenyl-stilbenes.

The solid-state fluorescence (SSF) of eight DPA-DPS-EWG derivatives (DPA = diphenylamino, DPS = 2,5-diphenyl-stilbene building block, EWG = electron withdrawing group) was studied. Varying the strength of the EWG enabled the tuning of the LUMO energy within a range broader than 1 eV, while the simultaneous changes of HOMO energy were less than 0.1 eV, according to cyclic voltammetry.

Green-, Red-, and Infrared-Emitting Polymorphs of Sterically Hindered Push-Pull Substituted Stilbenes.

The synthesis, XRD single-crystal structure, powder XRD, and solid-state fluorescence of two new DPA-DPS-EWG derivatives (DPA=diphenylamino, DPS=2,5-diphenyl-stilbene, EWG=electron-withdrawing group, that is, carbaldehyde or dicyanovinylene, DCV) are described. Absorption and fluorescence maxima in solvents of various polarity show bathochromic shifts with respect to the parent DPA-stilbene-EWGs. The electronic coupling in dimers and potential twist elasticity of monomers were studied by density functional theory.