Time integral and time differential Mössbauer measurements on [57Co/Mn(bipy)3](PF6)2

The Mössbauer emission spectra of nucleogenic iron(II) complexes with a low spin (LS) ground state show two metastable iron(II) high spin (HS) states at low temperatures. In order to identify these metastable HS states, the compound [⁵⁷Co/Mn(bipyridine)₃](PF₆)₂ has been studied by time differential Mössbauer emission spectroscopy (TDMES) and optical lifetime measurements of excited electronic states in the corresponding Fe-doped Mn compound. The lifetime of one of the HS states of the nucleogenic iron(II) determined by TDMES has been measured to be the same as the lifetime of the laser-excited iron(II) electronic state.