Critical temperature of the LIESST effect in a series of hydrated and anhydrous complex salts [Fe(bpp)2]X2

The magnetic properties of a series of hydrated and dehydrated spin crossover compounds derived from the 2,6-bis(pyrazol-3-yl)pyridine (bpp) ligand have been reinvestigated and the light-induced crossover studied at 10 K. The capacity of a compound to retain the light-induced HS information has been estimated through the determination of the T(LIESST). The position of each compound in the T(LIESST)–T1/2 diagram has been analyzed and the effect of the nature of the salt, hydration degree and cooperativity have been discussed.