CHEMISTRYSELECT, no.6, pp.11392-11406, 2021 (SCI-Expanded)
In
this study to analyze the structure-property
relationship of synthesized π-conjugated acrylonitrile derivative in terms of polymorphism
dependent emission and conformational polymorphism, single crystal x-ray
diffraction method, photophysical and theoretical studies were performed. The fluorescent molecule
with two polymorphic structure were presented to demonstrate the effect of the
molecular conformation and stacking type on the
polymorphism dependent emission in aggregate state. According to results of
crystallography and photophysical studies, both form of the molecule
displayed aggregation induced enhanced emission (AIEE) property in the solid
phase due to the restricted intramolecular rotation (RIR) and favourable stacking interactions including the
antiparallel H type, J type stacking
modes and intramolecular charge transfer (ICT) process. As a result, J type and antiparallel H type stacking mode with the restricted
intramolecular rotation make the crystals higly emissive in solid phase. We
believe that, studied two polymorphs will be best candidates for the π-conjugated
acrylonitrile derivatives in the optoelectronic field. Moreover, this study
will provide an overview of the importance of conformational polymorphism, stacking
type on fluorescence properties of the polymorphic structures and propose new ways for targeted polymorphic molecular design strategies in acrylonitrile derivatives.