Abstract: An iron(II) complex with nitronyl nitroxides, [FeII(dppNN)2](BF4)2 ·CH3COCH3 (1) (dppNN=2,6-di(pyrazol-1-yl)-4-(4,4,5,5-tetramethyl-1-oxido-3-ylooxy-4,5-dihydro-3H-imidazol-2′-yl)pyridine) was synthesized. In 1 the central iron(II) ion was coordinated by two tridentate ligands with nitronyl nitroxides. Magnetic susceptibility measurements showed that χ m T values below 130K was almost temperature independent, while upon increasing temperature χ m T values showed gradual increase, suggesting an occurrence of a spin transition from low to high spin state. Green light irradiation on powder sample at 5K resulted in spin conversion (LIESST). [Copyright &y& Elsevier]