Synthesis and magnetic properties of an iron 1,2-bisthienyl perfluorocyclopentene photochromic coordination compound

The coordination compound Fe(BM-4-PTP)2(NCS)2⋅2MeOH (1) including the photoisomerizable ligand BM-4-PTP (1,2-bis(2′-methyl-5′-(pyrid-4″-yl)thien-3′-yl)perfluorocyclopentene) was obtained as an orange powder. The powder turns blue upon photocyclization of the 1,2-bisthienyl photochromic ligand induced by UV light irradiation at room temperature. Photocycloreversion is obtained by visible light irradiation of the material in the solid state. The orange and blue powders were investigated over the temperature range (5–293 K) and pressure range (1 bar–12 kbar) by magnetic susceptibility measurements and variable temperature 57Fe Mössbauer spectroscopy. The photo-induced colour change is accompanied by a distinct magnetic variation at room temperature. Potentialities of this functional optical material for display and data recording are introduced.

An iron coordination compound presenting a distinct photomagnetic change at room temperature (See Figure) upon photocyclization of a diarylethene type ligand, together with a pronounced reversible photochromic effect in the solid state is reported. Potentialities of this functional material for display and data recording are introduced.Figure optionsDownload high-quality image (75 K)Download as PowerPoint slideResearch highlights
► An iron complex presenting both photomagnetic and photochromic properties.
► Optical and magnetic switching observed in the solid state at room temperature.
► No thermally induced spin crossover for this diarylethene Fe complex.
► Photomagnetism explained by a (L·)− radical in equilibrium with Fe(II,III) ions.
► Insertion into a light sensitive RLC logic operational circuit is proposed.