Multifunctional solid luminophores based on metal complexes: from luminescent molecular magnets to luminescent molecular ferroelectrics

The molecular building blocks approach has been demonstrated as a great strategy for the design and synthesis of diverse luminescent materials exhibiting strong room-temperature photo- and electroluminescence, which opens the broad application potential in optical sensing, bioimaging, data storage, anticounterfeiting, optoelectronics, optical amplification, photovoltaics, photocatalysis, and others.[1–3] Among a few different pathways explored within this synthetic approach, my research group focuses mainly on the application of purposefully designed metal complexes that can generate desired luminescent functionalities after the self-assembly into crystalline solids. Moreover, we aim at the design of multifunctional solid luminophores based on metal complexes, which combine light emission effects with other physical properties, including magnetic and electrical ones, chirality, and sensitivity to external stimuli.[4–8] In this contribution, I will discuss our main achievements in the construction of luminescent molecular nanomagnets and photomagnets based on lanthanide(III) complexes inserted into heterometallic coordination compounds,[4,9] in particular coordination polymers (CPs).[10–12] I will also present the more recent modification of synthetic strategies towards the design of luminescent molecular ferroelectrics using similar metal complexes, but differently self-assembled, i.e., into molecular hybrids with organic counter-ions.[13,14] Thus, the pathway from luminescent molecular magnets to luminescent molecular ferroelectrics, with the potential for their future merging, will be discussed.

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[2] P. Li, Z. Zhou, Y. S. Zhao, Y. Yan, Recent advances in luminescent metal–organic frameworks and their photonic applications, Chem. Commun. 2021, 57, 13678.
[3] D. Zhao, X. Xu, D. Yang, H. Li, Luminescent lanthanide hybrid materials: from molecular design to anti-counterfeiting application, Coord. Chem. Rev. 2026, 551, 217474.
[4] J. Wang, J. J. Zakrzewski, M. Heczko, M. Zychowicz, K. Nakagawa, K. Nakabayashi, B. Sieklucka, S. Chorazy, S. Ohkoshi, Proton Conductive Luminescent Thermometer Based on Near-Infrared Emissive {YbCo2} Molecular Nanomagnets, J. Am. Chem. Soc. 2020, 142, 3970.
[5] K. Boidachenko, M. Liberka, J. Wang, H. Tokoro, S. Ohkoshi, S. Chorazy, Chiral cadmium–amine complexes for stimulating non-linear optical activity and photoluminescence in solids based on aurophilic stacks, J. Mater. Chem. C 2024, 12, 14964.
[6] A. Hoffman, M. Zychowicz, J. Wang, K. Matsuura, F. Kagawa, J. Rzepiela, M. Heczko, S. Baś, H. Tokoro, S. Ohkoshi, S. Chorazy, Photoluminescent, dielectric, and magnetic responsivity to the humidity variation in SHG-active pyroelectric manganese(II)-based molecular material, Chem. Sci. 2025, 16, 8979.
[7] M. Niemiec, J. J. Zakrzewski, M. Reczyński, S. Chorazy, Proton Conductive Metal-Organic Framework Encapsulating Emissive Hexacyanidochromate(III) Ions for Ratiometric and Lifetime-Based Detection of Humidity and Temperature, Adv. Optical Mater. 2025, 13, 2404564.
[8] J. J. Zakrzewski, A. Hoffman, J. Wang, M. Pander, D. Matoga, H. Tokoro, S. Ohkoshi, S. Chorazy, Proton Conduction, Dielectric Relaxation, Photoluminescence, and Photochromism Governed by Humidity and Alcohol Vapors in a Uranyl–Cobalt Framework with Labile Coordination Sites, Angew. Chem. Int. Ed. 2025, 64, e202517109.
[9] J. Wang, J. J. Zakrzewski, M. Zychowicz, V. Vieru, L. F. Chibotaru, K. Nakabayashi, S. Chorazy, S. Ohkoshi, Holmium(III) molecular nanomagnets for optical thermometry exploring the luminescence reabsorption effect, Chem. Sci. 2021, 12, 730.
[10] Y. Xin, J. Wang, M. Zychowicz, J. J. Zakrzewski, K. Nakabayashi, B. Sieklucka, S. Chorazy, S. Ohkoshi, Dehydration–Hydration Switching of Single-Molecule Magnet Behavior and Visible Photoluminescence in a Cyanido-Bridged DyIIICoIII Framework. J. Am. Chem. Soc. 2019, 141, 18211.
[11] J. Wang, J. J. Zakrzewski, M. Zychowicz, Y. Xin, H. Tokoro, S. Chorazy, S. Ohkoshi, Desolvation-Induced Highly Symmetrical Terbium(III) Single-Molecule Magnet Exhibiting Luminescent Self-Monitoring of Temperature, Angew. Chem. Int. Ed. 2023, 62, e202306372. 
[12] J. J. Zakrzewski, R. Jankowski, M. Romanowska, J. Wang, D. Pinkowicz, B. Sieklucka, S. Ohkoshi, S. Chorazy, Luminescent Detection of Photomagnetic Effect in a Near-Infrared Emissive Neodymium(III)–Octacyanidotungstate(IV) Framework, Angew. Chem. Int. Ed. 2025, 64, e202424651.
[13] M. Liberka, M. Zychowicz, J. Hooper, K. Nakabayashi, S. Ohkoshi, S. Chorazy, Synchronous Switching of Dielectric Constant and Photoluminescence in Cyanidonitridorhenate-Based Crystals, Angew. Chem. Int. Ed. 2023, 62, e202308284.
[14] P. Bonarek, J. Rzepiela, M. Liberka, J. J. Zakrzewski, K. Wolski, J. Wang, H. Tokoro, S. Ohkoshi, F. Kagawa, S. Chorazy, Green-Emissive Ferroelectric Optical Thermometer Based on Cyclometalated Dicyanidoplatinate (II) Ions, ChemRxiv 2025, 10.26434/chemrxiv-2025-70v85.