Interplay between kinetically slow thermal spin-crossover and metastable high-spin state relaxation in an iron(II) complex with similar T1/2 and T(LIESST)

Victoria A. Money (1) , Chiara Carbonera (2) , Jérôme Elhaïk (3) , Malcolm A. Halcrow (3) , Judith A. K. Howard (1) , Jean-François Létard (2)

1 Chemical Crystallography Group, Chemistry Department
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
3 School of Chemistry [Leeds]

his paper describes the first material to show the well-known light-induced excited spin-state trapping (LIESST) effect, the metastable excited state of which relaxes at a temperature approaching its thermal spin-crossover. Cooling polycrystalline [FeL2][BF4]2x H2O (L=2,6-bis{3-methylpyrazol-1-yl}pyridine; x=0-1/3) at 1 K min-1 leads to a cooperative spin transition, taking place in two steps centered at 147 and 105 K, that is only 54 % complete by magnetic susceptibility...

Mots clés: Coordination chemistry; Iron; Magnetic properties; Photomagnetism; Spin crossover

Domaines: Matériaux

Victoria A. Money, Chiara Carbonera, Jérôme Elhaïk, Malcolm A. Halcrow, Judith A. K. Howard, et al.. Interplay between kinetically slow thermal spin-crossover and metastable high-spin state relaxation in an iron(II) complex with similar T1/2 and T(LIESST). Chemistry - A European Journal, 2007, 13 (19), pp.5503-5514. ⟨10.1002/chem.200601312⟩. ⟨hal-00160388⟩