Photoinduced Mo-CN Bond Breakage in Octacyanomolybdate Leading to Spin Triplet Trapping

Identifier:  imarina:6051412

Handle: https://hdl.handle.net/20.500.11797/imarina6051412

Authors:  Qi, XH; Pillet, S; de Graaf, C; Magott, M; Bendeif, EE; Guionneau, P; Rouzières, M; Marvaud, V; Stefanczyk, O; Pinkowicz, D; Mathonière, C

Abstract:
The photoinduced properties of the octacoordinated complex K4MoIV(CN)(0) center dot 2 H2O were studied by theoretical calculations, crystallography, and optical and magnetic measurements. The crystal structure recorded at 10 K after blue light irradiation reveals an heptacoordinated Mo(CN)(7) species originating from the light-induced cleavage of one Mo-CN bond, concomitant with the photoinduced formation of a paramagnetic signal. When this complex is heated to 70 K, it returns to its original diamagnetic ground state, demonstrating full reversibility. The photomagnetic properties show a partial conversion into a triplet state possessing significant magnetic anisotropy, which is in agreement with theoretical studies. Inspired by these results, we isolated the new compound [K(crypt-222)](3)[Mo-IV(CN)(7)] center dot 3 CH3CN using a photochemical pathway, confirming that photodissociation leads to a stable heptacyanomolybdate(IV) species in solution.