Nature of ColorDiversity in Phenylenevinylene-BasedPolymorphs

In this work we present a joint experimental and theoretical study of the light emitting properties of (E,E)-2,5-dimethoxy-1,4-bis[2-(4-carboxylatestyryl)]benzene, a phenylenevinylene (PV, from now on) derivative in the solid state. Careful crystal growth under different conditions of this PV luminophore yields three different crystals with dissimilar color emissions with maxima ranging between 504 and 565 nm. Single crystal structure elucidations indicate that they correspond to a DMF solvate, denoted 2·DMF (yellow) and two conformational polymorphs named 2α (yellow) and 2β (orange). Analysis of the close contacts and the framework topologies help us to rationalize the different colors observed, not only on the basis of different intramolecular conformations but also of the different intermolecular interactions observed. Particularly, the presence of different C–H···π and π···π interactions in 2α and in 2β polymorphs, respectively, give rise to different supramolecular frameworks with hex and bcu topolog...