1D iron(II) spin crossover coordination polymers with 3,3′-azopyridine – kinetic trapping effects and spin transition above room temperature

Two new iron(II) 1D coordination polymers with spin crossover behaviour were synthesised using 3,3'-azopyridine as bridging axial ligand and N2O2 coordinating Schiff base-like equatorial ligands. The X-ray structures of both complexes were solved revealing very different packing patterns for the two complexes. Magnetic measurements reveal a spin transition with hysteresis and kinetic trapping effects at lower temperatures for one complex and a spin transition above room temperature for the second complex.