Near-infrared-II photothermal conversion and magnetic dynamic regulation in [Ln 3 Rad 2 ] aggregation by rigidity modification of nitronyl nitroxide

• Published in: Inorganic chemistry frontiers
• Main Authors: Li, Hongdao, Jin, Chaoyi, Han, Jing, Tang, Jianke, Han, Xiaofeng, Song, Zhenjun
• Format: Journal Article
• Language: English
• Published: 19.10.2024
• ISSN: 2052-1553; 2052-1553
• DOI: 10.1039/D4QI01952K

Radical-metal compounds used as functional materials can be applied to multiple fields such as solar-thermal conversion and ultra-high density data storage. However, the reactivity and instability of organic radicals usually hamper the development and application of radical-metal compounds. Herein, we utilized persistent nitronyl nitroxide to construct two categories of nitronyl nitroxide-Ln compounds, [Gd 3 (hfac) 9 (NIT4bpym) 2 ] 2 ·4CH 2 Cl 2 ·C 6 H 14 (1-Gd), [Dy 3 (hfac) 9 (NIT4bpym) 2 ] (1-Dy) and [Dy 3 (hfac) 9 (NITPzCH 2 IM) 2 ]·2CH 2 Cl 2 (2-Dy) (NIT4bpym = 2,2′-dipyridyl-4-(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl-4,5-hydro-1 H -imidazol-2-yl); NITPzCH 2 IM = [2-(1-methylimidazole)methyl-1-pyrazol]-4-(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl-4,5-hydro-1 H -imidazol-2-yl) (hfac = hexafluoroacetylacetonate), involving a rare [4f–2p–4f–2p–4f] multi-spin motif with an electron donor–acceptor pattern. Notably, thanks to the rigidity modification of nitronyl nitroxide, prominent enhancement of photothermal conversion efficiency from 56.9% to 74.0% and the magnetic switching phenomenon have been observed with molecular structure transformation from flexibility (2-Dy) to stiffness (1-Dy), offering an avenue for the regulation of the photothermal effect and magnetic dynamics.