Synthesis, Structure, and Photomagnetic Properties of a Hydrogen-Bonded Lattice of [Fe(bpp) 2 ] 2+ Spin-Crossover Complexes and Nicotinate Anions

摘要

In this paper, we report on the synthesis, crystal structure, and photomagnetic properties of the spin-crossover salt of formula [Fe(bpp) 2 ](C 6 H 4 NO 2 ) 2 ·4H 2 O ( 1 ·4H 2 O) (bpp = 2,6-bis(pyrazol-3-yl)pyridine; C 6 H 4 NO 2 ? = nicotinate anion). This compound exhibits a 3D supramolecular architecture built from hydrogen bonds between iron(II) complexes, nicotinate anions, and water molecules. As synthesized, the hydrated material is low-spin and desolvation triggers a low-spin (LS) to high-spin (HS) transformation. Anhydrous phase 1 undergoes a partial spin crossover ( T 1/2 = 281 K) and a LS to HS photomagnetic conversion with a T (LIESST) value of 56 K.