%0 Journal Article %A Lannes, Anthony %A Suffren, Yan %A Tommasino, Jean Bernard %A Chiriac, Rodica %A Toche, François %A Khrouz, Lhoussain %A Molton, Florian %A Duboc, Carole %A Kieffer, Isabelle %A Hazemann, Jean-Louis %A Reber, Christian %A Hauser, Andreas %A Luneau, Dominique %T Room Temperature Magnetic Switchability Assisted by Hysteretic Valence Tautomerism in a Layered Two Dimensional Manganese-Radical Coordination Framework %J Journal of the American Chemical Society %@ 0002-7863 %V 138 %N 50 %P 16493-16501 %D 2016 %U http://pubs.acs.org/doi/abs/10.1021/jacs.6b10544 %R 10.1021/jacs.6b10544 %U http://archive-ouverte.unige.ch/unige:90821 %X The manganese-nitronyl-nitroxide two dimensional coordination polymer {[Mn2(NITIm)3]ClO4}n (1) (NITImH = 2-(2-imidazolyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-3-oxide-1-oxyl) undergoes an unusual hysteretic thermoinduced valence tautomeric transition near room temperature, during which the manganese(II) ions are oxidized to manganese(III) and two of the three deprotonated radicals (NITIm-) are reduced to their diamagnetic aminoxyl form (denoted NITImRed2-). Upon cooling, the high-temperature species {[MnII2(NITIm)3]ClO4}n (1HT) turns into the low-temperature species {[MnIII2(NITImRed)2(NITIm)]ClO4}n (1LT) around 274 K, while on heating the process is reversed at about 287 K. This valence tautomeric phenomenon is supported by temperature-dependent magnetic susceptibility measurements, differential scanning calorimetry (DSC), crystal structure determination, UV-vis absorption, X-ray absorption (XAS) an emission (XES) and Electron Paramagnetic Resonance (EPR) spectroscopies in the solid-state.