Pressure Effect Studies on the High Spin ⇆ Low Spin Transition Behavior Observed in [Fe(II)(bpp)2](NCS)2.2H2O

Background: [Fe(bpp)2](NCS)2.2H2O exhibits a two-step spin transition between the 5T2 state (HS, S = 2) and the 1A1 state (LS, S = 0) below room temperature, both steps being associated with thermal hysteresis. The present study explored the nature of spin transition (ST) in [Fe(bpp)2](NCS)2.2H2O under pressure to determine if ST could be induced to go to completion and whether a two-step process was then involved. Keywords: Spin transition, Fe(II), high pressure, magnetization, pressure effect studies, spin crossover.