abstract
The development of photoresponsive ferroelastics, which couple light-induced macroscopic mechanical and microscopic domain properties, represents a frontier in materials science with profound implications for advanced functional applications. In this study, we report the rational design and synthesis of two new organic–inorganic hybrid ferroelastic crystals, (MA)(Me4N)[Fe(CN)5(NO)] (MA = methylammonium) (1) and (MA)(Me3NOH)[Fe(CN)5(NO)] (2), using a dual-organic molecular design strategy that exploits hydrogen-bonding interactions for tailoring ferroelastic properties. Specifically, 1 exhibits a two-step phase transition at 138 and 242 K, while the introduction of a hydroxyl group in 2 stabilizes its ferroelastic phase to a significantly higher temperature, achieving a phase transition at 328 K, 86 K above that of 1. This enhancement is attributed to hydrogen bonding between the hydroxyl group of Me3NOH+ and the nitroprusside anion, which suppresses lattice dynamics and reinforces structural stability. Remarkably, 2 demonstrates a large spontaneous strain of 0.153, vastly exceeding the 0.021 of 1, and undergoes an 11% size change along the b-axis in response to thermal stimuli. Both compounds exhibit reversible, photoinduced nitrosyl-linkage isomerization, as confirmed by IR spectroscopy, transitioning between the ground state (N-bound nitrosyl) and the metastable state (O-bound nitrosyl). This integration of photoresponsive functionality with ferroelastic properties establishes a versatile platform for energy-efficient actuation, adaptive devices, and multifunctional sensing applications. These findings offer an innovative pathway for designing next-generation hybrid materials with enhanced tunable properties.
authors
Luis Verissimo; Zi-Luo Fang; Wei-Jian Xu; José M. G. Martinho; Wei Yuan; Wei-Xiong; Zhang, Andrei Kholkin, João Rocha
our authors
Andrei Kholkin
Retired Researcher
João Rocha
Full Professor
Luís Veríssimo
PhD Student
Wei-Jian Xu
Junior ResearcherProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
Redox-active Metal-Organic Frameworks as Electrode Materials for Lithium-Ion Batteries (RedoxMOFs)
Other
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Mediaacknowledgements
This work was supported by NSFC (22071273 and 21821003), Fundamental Research Funds for the Central Universities (23lgzy001). This work was also developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement. It is also funded by national funds (OE), through FCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5, and 6 of the article 23, of the Decree-Law 57/2016, of August 29th, changed by Law 57/2017, of July 19th. We thank FCT for funding the project PTDC/QUI-ELT/2593/2021 and PTDC/CTM-CTM/4044/2020 grants. L.V. thanks FCT for UI/BD/151050/2021. J.M.G.M thanks FCT and COMPETE (FEDER) for the projects UIDB/00100/2020, UIDP/00100/2020, and LA/P/0056/2020. A.K. acknowledges the project “FeLow-D” funded under the Horizon Europe programme HORIZON-WIDERA-2023-TALENTS-01, GA nr.101186499.