Chemical design enables the control of conformational polymorphism in functional 2,3-thieno(bis)imide-ended materials

Abstract

We report a successful chemical design strategy based on the even-odd alkyl end tailoring, which allows us to promote and control conformational polymorphism in single crystal and thin deposits of thienoimide-based molecular semiconductors (Cx-NT4N).

Reversible fluorescence switching and topochemical conversion in an organic AEE material: polymorphism, defection and nanofabrication mediated fluorescence tuning

“…[26][27][28][29] Switching and tuning of organic solid state fluorescence could be realized by controlling the molecular arrangement, conformation and intermolecular interactions. [30][31][32][33] External stimuli such as heat, mechanical force and solvent exposure often changes the molecular conformation or phase of the materials (crystalline to amorphous) and switches the fluorescence. [30][31][32][33] External stimuli such as heat, mechanical force and solvent exposure often changes the molecular conformation or phase of the materials (crystalline to amorphous) and switches the fluorescence.…”

Organic Materials for Time–Temperature Integrator Devices

“…61,62 In thienoimide-based molecular materials, recently exploited by our group for TTI fabrication, 29 The thienoimide moiety itself induces conformational polymorphism, i.e., the possibility of different molecular conformation by rotation of the thiophene ring adjacent to the thienoimide moiety with respect to the thienoimide. 42 Indeed, an even−odd effect of the N-alkyl end on the molecular conformation type and crystal packing has recently been reported for these molecules and was reflected in the emission color of microcrystals deposited on the substrates. Figure 10 shows the fluorescence microscopy images of microfiber and crystallite evolution of the fluorescence color for a thienoimidebased trimer (Figure 9e) by heating the thin deposits up to 200°C .…”

Tuning polymorphism in 2,3-thienoimide capped oligothiophene based field-effect transistors by implementing vacuum and solution deposition methods

“…16 We have recently reported on the relationship between the molecular structures and polymorphism properties of C n -NT4N derivatives. 17 Interestingly, C n -NT4N derivatives with an even number of carbon atoms in the alkyl end chains display at least two conformational polymorphs that adopt different molecular packings, namely phase A and phase B, as a consequence of the different conformational arrangement of the 2,3-thienoimide end-moieties with respect to the adjacent thiophene core, i.e. anti or syn conformation ( Fig.…”

“…1b). 17 The occurrence of different molecular packings may limit the reproducibility, stability, and reliability of devices based on these materials, therefore, the control of polymorph formation during film deposition is crucial for their applicability.…”