Light induced excited spin state trapping in the binuclear spin crossover compound [Fe(bpym)(NCS)(2)](2)(bpym) exhibiting a high-spin ground state

摘要

A photo-magnetic effect is evidenced using near-infrared light in the binuclear complex [ Fe (bpym)(NCS)(2)](2)( bpym). This compound has a T-5(2g)-T-5(2g) ground state and exhibits no thermal spin crossover - in contrast to the analogous [Fe(bpym)(NCSe)(2)](2)(bpym). The estimated photo-conversion ratio is ca. 30%. By means of magnetic susceptibility measurements as well as Raman and infrared absorption spectroscopies, the nature of the photo-induced phase was established as the T-5(2g)-(1)A(1g) state, which means that only one iron center is converted to low-spin. The photo-induced state was completely converted back to the ground state either by visible light excitation or by heating.