Mechanoresponsive luminescent (MRL) materials have attracted considerable attention because of their potential applications in mechanical sensors, memory chips, and security inks; MRL materials possessing high efficiency and multicolor emission qualities are especially interesting. In this Letter, we found 1,2,3,4-tetraphenyl-1,3-cyclopentadiene (TPC) crystal exhibited both pressure-induced emission enhancement (PIEE) and multicolor behavior. In addition, infrared spectroscopy analysis indicated that the ring-opening reaction of the phenyl ring occurred when pressure was beyond 24.7 GPa. The reaction was promoted from 24.7 to 35.9 GPa, which resulted in the redder irreversible color change for the sample released from 35.9 GPa than from 24.7 GPa. The results regarding the mechanoresponsive behavior of TPC offered a deep insight into PIEE and multicolor properties from the structural point of view and inspired the idea of capturing different colors by hydrostatic pressure, which will facilitate the design of and search for high-performance MRL materials.

中文翻译：

---

1,2,3,4-四苯基-1,3-环戊二烯的压力诱导发射增强和多色发射：受控的结构演变

机械响应发光（MRL）材料由于在机械传感器，存储芯片和安全油墨中的潜在应用而备受关注。具有高效率和多色发射质量的MRL材料尤其令人感兴趣。在这封信中，我们发现1,2,3,4-四苯基-1,3-环戊二烯（TPC）晶体既表现出压力诱导的发射增强（PIEE），又表现出多色行为。另外，红外光谱分析表明当压力超过24.7GPa时发生苯环的开环反应。反应从24.7 GPa提升到35.9 GPa，导致从35.9 GPa释放的样品比从24.7 GPa的样品发生不可逆的更红的颜色变化。