Polymorphic and mechanochromic luminescence modulation in the highly emissive dicyanodistyrylbenzene crystal: secondary bonding interaction in molecular stacking assembly

• DOI: 10.1039/c0jm03711g
• Publication Date: 2011-01-24T10:00:39Z
• Authors: Seong-Jun Yoon; SooYoung Park
• Keywords: Crystal (programming language)

Understanding the role of self-assembly and electronic interactions constituent molecules in determining optoelectronic properties a molecular solid is fundamental essential issue material science. Particularly, correlation between stacking mode modulated optical has barely been established spite its scientific technological importance. Herein, we present dicyanodistyrylbenzene-based highly luminescent crystals which uniquely exhibit polymorphism mechanochromism. In these materials, various secondary bonding (local dipole interaction, C–H⋯π C–H⋯N hydrogen bond) play key roles assembly, as well polymorphic mechanochromic behaviors. The two different phases dicyanodistyrylbenzene crystal were correlated to modes local coupling, caused substantial alternation π–π overlap excited state delocalization give differently colored fluorescence emission. Most uniquely, phase transformation those crystalline was effected through thermal mechanical processes. We have comprehensively carried out in-depth systematic optical, structural, photophysical investigations establish unambiguous structure–property relationships.