Related Experiment Video
Updated: Nov 6, 2025

An Electrochemical Cholesteric Liquid Crystalline Device for Quick and Low-Voltage Color Modulation
Published on: February 27, 2019
Reverse Hofmann-Type Spin-Crossover Compound Showing a Multichannel Controllable Color Change in an Ambient
Jing-Hua Yang1, Yan-Xin Zhao1, Jin-Peng Xue1
1Key Laboratory of Cluster Science of Ministry of Education, School of Chemistry and Chemical Engineering, Beijing Institute of Technology, Liangxiang Campus, Beijing 102488, People's Republic of China.
Abstract:
Materials that demonstrate a multichannel controllable color change in response to external stimuli are fascinating for their potential applications in sensoring and displaying devices. Herein we report a FeII spin-crossover (SCO) compound that exhibits both solvatochromism and thermochromism under an ambient environment. This Hofmann-type compound possesses two different pores where the solvent guests can be removed in a two-step process. Because the loss of solvent guests modifies the spin state of magnetic centers, an unusual yellow-red-yellow two-step color change of crystals was detected. Moreover, because of the strong cooperativity of the spin centers, a dramatic red-to-yellow color change of crystals in response to a minute thermal perturbation around 303 K is triggered by an abrupt spin transition of the metal centers. The multichannel controllable dramatic color change demonstrated in the present compound highlights the sensoring and displaying roles of SCO materials.
More Related Videos
Related Concept Videos
Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
Channel Rhodopsins
Rhodopsins belong to the family of cell surface proteins called G-protein coupled receptors,...
Color Vision
Photochemical Electrocyclic Reactions: Stereochemistry
Selection Rules: Photochemical Activation
UV–Vis Spectroscopy: Molecular Electronic Transitions
Variables Affecting Phosphorescence and Fluorescence

