Light-Induced, Structural Matrix Guided Stepwise Spin-State Switching in 3d-5d Molecular Assembly
Abstract
A new iron(II) molecular complex {[W(CN)8][Fe(bik*)3]2}BF4·7H2O·1.5CH3OH (1) was synthesized using versatile octacyanotungstate(V) building block and N-donor bidentate ligand (bik* = bis(1-ethyl-1H-imidazol-2-yl)ketone) and detailed characterization was carried out. The crystal structure of 1 is composed of the ionic salts of one anionic [W(CN)8]3- unit, two isolated cationic [Fe(bik*)3]2+ units and one BF4- counter ion in the asymmetric unit. Magnetic studies of 1 display interesting two-step reversible thermo-induced spin-state switching and photo-magnetic effect at low temperatures. Additionally, the physical properties of 1 were compared with the monomeric unit of {[Fe(bik*)3]2}4ReO4·H2O (2) and detailed photophysical studies were also carried out to investigate the effect of structural matrix {[W(CN)8]3- and ReO4- unit} on the spin-state switching properties of the [Fe(bik*)3]2+ unit on both systems (1 and 2).