Mechanochromism and Polymorphism-Dependent Emission of Tetrakis(4-(dimethylamino)phenyl)ethylene

The mechanochromic property of tetrakis(4-(dimethylamino)phenyl)ethylene (TDMAPE) with natural propeller shape and nearly centrosymmetric structure was investigated. The destruction of the crystalline structure leads to the planarization of molecular conformation, which is considered as a possible reason for the red-shift of absorption and fluorescence spectra after grinding. And the polymorphism-dependent emissions of the two polymorphs of TDMAPE are mainly determined by the intramolecular conformation, which show the increased coplanarity or conjugation degree, ultimately leading to the bathochromic shift of the emissions.