Dynamic Resolution of Piezosensitivity in Single Crystals of π-Conjugated Molecules |
| |
Authors: | Sohini Bhattacharyya Szymon Sobczak Aleksandra Półrolniczak Dr Syamantak Roy Dr Debabrata Samanta Prof Andrzej Katrusiak Prof Dr Tapas Kumar Maji |
| |
Institution: | 1. Chemistry and Physics of Materials Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, 560064 India;2. Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland;3. Faculty of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznań, Poland
These authors contributed equally to this work. |
| |
Abstract: | Targeted synthesis of piezoresponsive small molecules and in-depth understanding of their mechanism is of utmost importance for the development of smart devices. This work reports the synthesis, structure and piezosensitivity of a bola-amphiphile 1,4-bis(pentyloxy)-2,5-bis(2-pyridineethynyl)-benzene ( C5-PPB ). Depending on the rate of compression, two different phases in C5-PPB can be generated. The ambient-pressure α-phase is stable up to 0.8 GPa, beyond which it undergoes an isostructural transformation to β-phase, accompanied by a clearly visible elongation of the crystal. This α-to-β phase transition requires the sample to be compressed slowly. When quickly compressed, phase α persists to about 1.5 GPa, beyond which its amorphization starts, accompanied by the appearance of irregular grooves on the largest faces. Mechanical pressure also affects the optical property of C5-PPB , which shows reversible mechanochromism with a green to cyan transformation in the emission, associated with a 15 nm shift in the maxima. The conductivity of C5-PPB as a direct outcome of its crystal packing has also been studied. |
| |
Keywords: | bola-amphiphile chromophores high-pressure chemistry piezosensitive reversible mechanochromism |
|
|