First observation of photoinduced magnetization for the cyano-bridged 3d-4f heterobimetallic assembly Nd(DMF)₄(H₂O)₃(μ-CN)Fe(CN)₅.H₂O (DMF = N,N-dimethylformamide)

Photoinduced magnetization of the cyano-bridged 3d-4f hetero-bimetallic assembly Nd (DMF)₄(H₂O)₃(μ-CN)Fe(CN)₅.H₂O (1) (DMF = N,N-dimethylformamide) is described in this paper. The χM_T values are enhanced by about 45% after UV light illumination in the temperature range of 5-50 K. We propose that UV light illumination induces a structural distortion in 1. This small structural change is propagated by molecular interactions in the inorganic network. Furthermore, the cooperativity resulting from the molecular interaction functions to increase the activation energy of the relaxation processes, which makes observation of the photoexcited state possible. The flexible network structure through the hydrogen bonds in 1 plays an essential role for the photoinduced phenomenon. This finding may open up a new domain for developing molecule-based magnetic materials.