Photomagnetic studies of spin-crossover- and photochromic-based complexes

C. Faulmann (1) , Joe Chahine (1) , Lydie Valade (1) , Guillaume Chastanet (2) , Jean-François Létard (2) , Dominique de Caro (1)

1 LCC - Laboratoire de chimie de coordination
2 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux

This work reports on the combination between photochromic complexes (Na2[Fe(CN)5(NO)]*2H2O and K2[RuCl5(NO)]) with spin-crossover compounds derived from FeIII complexes {[Fe(qsal)2]+ and [Fe(salEen)2]+; Hqsal = N-(8-quinolyl)salicylaldimine; HsalEen = N-[(2-ethylamino)ethyl]salicylaldimine}. These associations have resulted in the synthesis of new materials that contain a spin-crossover unit and a photochromic unit, as evidenced by their X-ray structure. Spectroscopic, magnetic and photomagnetic properties of these complexes were studied, with or without light irradiation, to evaluate the possible influence of the photochromic group on the spin transition. [Fe(qsal)2]2[Fe(CN)5(NO)]*solvent, [Fe(salEen)2]2[Fe(CN)5(NO)] and [Fe(qsal)2]2[Ru(CN)5(NO)]*2.5H2O all exhibit a spin transition. The light-induced excited spin-state trapping (LIESST) effect was detected in the (Fe-qsal)-based complexes. [Fe(qsal)2]2[Ru(CN)5(NO)]*2.5H2O also exhibits a reverse-LIESST effect. Regardless of the complex, no photochromic effect from the nitroprusside units was detected.

Mots clés: Spin crossover; Photochromism; Magnetic properites; O ligands; Ruthenium; Iron; Nitroprussiate

Domaines: Matériaux

C. Faulmann, Joe Chahine, Lydie Valade, Guillaume Chastanet, Jean-François Létard, et al.. Photomagnetic studies of spin-crossover- and photochromic-based complexes. European Journal of Inorganic Chemistry, 2013, 5-6, pp.1058-1067. ⟨10.1002/ejic.201201328⟩. ⟨hal-00799418⟩