First ligand-driven light-induced spin change at room temperature in a transition-metal molecular compound

• DOI: 10.1039/a809504c
• Publication Date: 2002-07-26T09:17:16Z
• Authors: Marie-Laure Boillot; Sylvie Chantraine; Jacqueline Zaremb...; Jean-Yves Lallemand; Joëlle Prunet
• Keywords: Spin transition

Applied to the new iron(II) compound Fe(t-msbpy)2(NCS)2 (t-msbpy=4-methyl-4′-trans-styryl-2,2′-bipyridine), a novel strategy based on so-called ''ligand-driven light-induced spin change'' (or LD-LISC) effect, which consists in triggering metal ion electronic spin-state crossover complex by photochemical modification of ligand, allowed this photomagnetic effect be observed for first time at room temperature. The compound, studied CH3CN or CD3CN, was found initially nearly diamagnetic (S=0) means NMR experiments. Then, irradiation solution photostationary state with λexc=334 nm shown, using UV-VIS spectrometry, result trans→cis isomerization styryl substituent msbpy and subsequent S=0 (low spin)→S=2 (high spin) conversion significant fraction ions.