Photomagnetic switching of the complex [Nd(dmf)4(H2O)3(mu-CN)Fe(CN)5] x H2O analyzed by single-crystal X-ray diffraction.

X-ray vision: Single-crystal XRD experiments (see picture) reveal the excited-state structure of the photomagnetic heterobimetallic title complex. The system shows a decrease in all the iron-ligand bond lengths, suggesting that photoexcitation involves a ligand-to-metal charge transfer or a change in the superexchange coupling between the metal centers.