Demonstration of the thermally induced high spin-low spin transition for a transparent spin crossover complex film [Fe(II)(H-trz)3]-nafion (trz = triazole)

Transparent spin crossover complex films [Fe(R-trz)(3])-Nafion (R = H, NH2), have been prepared by using ail ion-exchange resin (Nafion) as counter anion. We observed the spin crossover phenomenon around room temperature and revealed the LIESST (light-induced excited spin state trapping) effect at 4.2 K, for these films. In ICMM2004, we have demonstrated the spin crossover behavior as thermochromism for the transparent [Fe(H-trz)(3)]-Nafion film, where the spin transition takes place between the high spin (HS) state (colorless at 300 K) and the low spin (LS) state (purple color at 77 K). Here, we review the synthesis and the spin crossover phenomenon for the spin crossover complex film [Fe(H-trz)(3)]-Nafion. (c) 2005 Elsevier Ltd. All rights reserved.