Photoelectron Spectroscopic Study on Photo-Induced Phase Transition of Spin-Crossover Complex

Valence band structures in various phases of an organometal spin-crossover complex [Fe(2-pic)3]Cl2EtOH have been measured by means of photoelectron spectroscopy based on the combination of synchrotron radiation and laser light. The valence band structure showed the remarkable change due to the photo-induced (PI) phase transition (PIPT) at low-temperatures (LTs) as well as the thermally induced phase transition (TIPT), but the structure of the PI phase was very different from that of the high-temperature (HT) phase. The DV-X calculation based on the [Fe-(NH3)6] octahedron was also carried out for comparison, indicating that the electronic structure originating from Fe and N ions is closely related to the PIPT