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

The coordination compound Fe(BM-4-PTP)2(NCS)(2)center dot 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 Fe-57 Mossbauer 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. (C) 2010 Elsevier B.V. All rights reserved.