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Green‐, Red‐, and Infrared‐Emitting Polymorphs of Sterically Hindered Push–Pull Substituted Stilbenes
Author(s) -
Pauk Karel,
Luňák Stanislav,
Růžička Aleš,
Marková Aneta,
Mausová Anna,
Kratochvíl Matouš,
Melánová Klára,
Weiter Martin,
Imramovský Aleš,
Vala Martin
Publication year - 2021
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.202004419
Subject(s) - bathochromic shift , fluorescence , monomer , photochemistry , excimer , chemistry , crystallography , density functional theory , derivative (finance) , materials science , computational chemistry , organic chemistry , polymer , quantum mechanics , financial economics , economics , physics
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. Both polymorphs of the CHO derivative emit green fluorescence (527 and 550 nm) of moderate intensity (10 % and 5 %) in polycrystalline powder form. Moderate (5 %) red (672 nm) monomer‐like emission was also observed for the first polymorph of the DCV derivative, whereas more intense (32 %) infrared (733 nm) emission of the second polymorph was ascribed to the excimer fluorescence.