Piezochromism Explained

Piezochromism, from the Greek piezô "to squeeze, to press" and chromos "color",^[1] describes the tendency of certain materials to change color with the application of pressure. This effect is closely related to the electronic band gap change, which can be found in plastics, semiconductors (e.g. hybrid perovskites)^{[2] [3] [4]} and hydrocarbons.^[5] One simple molecule displaying this property is 5-methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile, also known as ROY owing to its red, orange and yellow crystalline forms. Individual yellow and pale orange versions transform reversibly to red at high pressure.^[6]

External links

• Piezochromism

Notes and References

1. Web site: Piezochromes: pigments, inks, paints - OliKrom. 2022-02-16. Olikrom. 2022-10-20. Piezochromism (from the Greek piezô "to squeeze, to press" and chromos "the color") is by definition made of a material (pigment, dye...) whose optical properties change depending on macroscopic mechanical stimuli (pressure).
2. 10.1021/acs.jpclett.7b01367. Effects of Nonhydrostatic Stress on Structural and Optoelectronic Properties of Methylammonium Lead Bromide Perovskite. 2017. free. Zhang. Rong. Cai. Weizhao. Bi. Tiange. Zarifi. Niloofar. Terpstra. Tyson. Zhang. Chuang. Verdeny. Z. Valy. Zurek. Eva. Deemyad. Shanti. The Journal of Physical Chemistry Letters. 8. 15. 3457–3465. 28691486.
3. 10.1002/anie.201804310. Pressure‐Induced Emission Enhancement, Band‐Gap Narrowing, and Metallization of Halide Perovskite Cs₃Bi₂I₉. 2018. Zhang. Long. Liu. Chunming. Wang. Lingrui. Liu. Cailong. Wang. Kai. Zou. Bo. Angewandte Chemie International Edition. 57. 35. 11213–11217. 30010235. 51627681.
4. 10.1021/acs.jpclett.6b01648. Mechanism of Pressure-Induced Phase Transitions, Amorphization, and Absorption-Edge Shift in Photovoltaic Methylammonium Lead Iodide. 2016. free. Szafrański. Marek. Katrusiak. Andrzej. The Journal of Physical Chemistry Letters. 7. 17. 3458–3466. 27538989.
5. 10.1039/C6CP08171A. Piezochromism and structural and electronic properties of benz[a]anthracene under pressure . 2017 . Cai . Weizhao . Zhang . Rong . Yao . Yansun . Deemyad . Shanti . Physical Chemistry Chemical Physics. 19 . 8 . 6216–6223 . 28230219 . 2017PCCP...19.6216C .
6. 10.1039/d1sc04051k . Direct evidence for distinct colour origins in ROY polymorphs . 2021 . Warren . Lisette R . McGowan . Evana . Renton . Margaret . Morrison . Carole A . Funnell . Nicholas P . Chemical Science . 12 . 38. 12711–12718 . 34703557 . 8494124 .