MS31-P09 Understanding supramolecular role in mechanochromic luminescent polymorphs Marcelo Echeverri (Instituto de Ciencia de Materiales de Madrid, Madrid, Spain) Berta Gomez-Lor (Instituto de Ciencia de Materiales de Madrid, Madrid, Spain)email: m.echeverri@csic.esMechanochromic materials (i.e. solids possessing light emitting properties that vary upon mechanical grinding or pressing), arouse much interest in recording or sensing applications that involve luminescent detection. However, only in a few of them an adequate understanding about the origin of the color change has been achieved. Light-emitting single crystalline compounds are especially interesting for allowing correlating the changes in the solid-state luminescent properties with variations in the molecular or supramolecular structure.1
In the quest for efficient light emitting compounds, benzothiadiazole (BTD) is one of the preferred moieties. This electron deficient heterocycle presents high fluorescence quantum efficiencies and has a strong propensity to adopt quinoid conformations, thus facilitating charge transfer between attached substituents and enabling the tuning of its emission properties.2 Herein we present a new BTD-derivatives series, which each one crystallizes in two different polymorphs. These compounds change their light emitting properties due to slight changes of their crystallographic packing, offerings an excellent opportunity to establish optimal supramolecular arrangement for photonic applications.

(1) S. Varughese, J. Mater. Chem. C, 2014, 2, 3499-3516

(2) N. J. Findlay, B. Breig, C. Forbes, A. R. Inigo, A. L. Kanibolotsky and P. J. Skabara, J. Mater. Chem. C, 2016, 4, 3774-3780
Keywords: mechanochromic, luminescent, supramolecular