Two Magnetic Switching Complexes Based on the Fe(II) Ion.

Abstract

Two neutral mononuclear iron(II) complexes with different spin-crossover (SCO) properties, Fe(L1)2(SCN)2 (1) and Fe(L2)2(SCN)2 (2) (L1 = 2-(thiophen-3-yl)-1H-imidazo[4,5-f][1,10]phenanthroline and L2 = 2-(thiophen-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline), were solvothermally synthesized. With the different substituted position in 1,10-phenanthroline derivatives, 1 exhibits gradual SCO around room temperature with T1/2 = 280 K, while 2 displays abrupt SCO with 10 K hysteresis at T1/2↓ = 210 K and T1/2↑ = 220 K.