X-ray absorption spectroscopic studies on light-induced excited spin statetrapping of an Fe(II) complex

Light-induced excited spin state trapping of Fe(phen)(2)(NCS)(2) is studied by X-ray absorption spectroscopy using synchrotron radiation. The molecula r structure of the excited high-spin state at 17 K is investigated by EXAFS . The relaxation of the light-induced high-spin state at various temperatur es is monitored through the absorption spectra. The concurrent abrupt latti ce change with the change in electronic configuration is observed through s ingle crystal X-ray diffraction. The lattice cooperative effect is importan t in the relaxation behavior. The magnetic property and the relaxation beha vior of two differently prepared samples are distinctly different.