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Updated: Apr 2, 2026

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Reversible phase-transformation-induced thermal quenching in Mn(II) chlorides for high-precision information
Aibo Li1, Zongqi Chen1, Zhengliang Wang2
1Key Laboratory of Green-chemistry Materials in University of Yunnan Province, National and Local Joint Engineering Research Center for Green Preparation Technology of Biobased Materials, School of Chemistry & Environment, Yunnan Minzu University, Kunming, China.
Abstract:
Photoluminescent materials are widely used in information security applications, yet high-precision optical information encryption remains difficult to achieve. Here we report two monoclinic zero-dimensional organic-inorganic hybrid Mn(II) chloride crystals (C19H42N)2MnCl4 and (C21H46N)2MnCl4. Both show green emission with photoluminescence quantum yields of 85.7% and 89.3%. Upon heating, photoluminescence (PL) is quenched abruptly at 333 and 343 K (ΔT = 10 K) and recovers upon cooling, driven by reversible order-disorder solid-solid phase transitions with phase-transition enthalpies of 140.6 and 160.3 J g-1, respectively. Using two closely spaced PL quenching temperatures, we demonstrate a temperature-window encryption scheme for optical information encryption and anti-counterfeiting, where correct information is revealed only within 333 ≤ T < 343 K. Furthermore, combining latent-heat storage with a temperature-gated PL ON/OFF readout provides a straightforward route to visualized thermal energy storage. This work reveals phase-transition-induced PL quenching and its applications in optical information encryption and visualized thermal energy storage, providing a strategy for designing multifunctional thermo-responsive luminescent materials.
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