Twist‐Elasticity‐Controlled Crystal Emission in Highly Luminescent Polymorphs of Cyano‐Substituted Distyrylbenzene (βDCS)

• Published in: Advanced optical materials 2017-11, Vol.5 (21), p.n/a
• Main Authors: Shi, Junqing, Yoon, Seong‐Jun, Viani, Lucas, Park, Soo Young, Milián‐Medina, Begoña, Gierschner, Johannes
• Format: Article
• Language: English
• Subjects: Broadband; conjugated organic materials; Elasticity; Emissions control; fluorescence; lasing; Materials science; Optics; Optoelectronics; Organic materials; quantum chemistry; single crystals; Stimulated emission
• ISSN: 2195-1071; 2195-1071
• DOI: 10.1002/adom.201700340

The occurrence of polymorphs in crystals of luminescent π‐conjugated organic materials is an intriguing matter, particularly because polymorphs can give rise to widely different broadband and amplified emission properties. Here, a new, highly luminescent polymorph of cyano‐substituted distyrylbenzene, being a prominent example of “twist elasticity”—the ability of a molecule to react to external constraints with substantial changes in the torsional coordinates, is investigated. The twist elasticity concept is fully explored here through molecular modeling by comparison of the new polymorph with two known ones exhibiting largely different intra‐ and intermolecular coordinates. In a second step, the impact of intra‐ and intermolecular contributions on the spontaneous and stimulated emission properties observed in the crystals is rationalized, being in all a crucial step in targeted design of optoelectronic materials. Twist elasticity—a molecule's ability to react to external constraints with substantial changes in the torsional coordinates—is explored on different crystal polymorphs of cyano‐substituted distyrylbenzene, a luminescent π‐conjugated compound; the polymorphs' varying emission properties are decided by a subtle interplay of intra‐ and intermolecular contributions.