A spin-crossover complex based on a 2,6-bis(pyrazol-1-yl) pyridine (1-bpp) ligand functionalized with a carboxylate group

Combining Fe(II) with the carboxylate-functionalized 2,6-bis(pyrazol-1-yl) pyridine (bppCOOH) ligand results in the spin-crossover compound [Fe(bppCOOH)(2)](ClO4)(2) which shows an abrupt spin transition with a T-1/2 of ca. 380 K and a T-LIESST of 60 K due to the presence of a hydrogen-bonded linear network of complexes.