@Article{InorgChem_44_5530, author = {B.P. Macpherson and P.V. Bernhardt and A. Hauser and S. Pag{\`e}s and E. Vauthey}, title = {{Time-Resolved Spectroscopy of the Metal-to-Metal Charge Transfer Excited State in Dinuclear Cyano-Bridged Mixed-Valence Complexes}}, journal= {Inorg. Chem.}, ISSN = {0020-1669}, volume= {44}, number= {15}, pages = {5530-5536}, url = {http://pubs.acs.org/cgi-bin/abstract.cgi/inocaj/2005/44/i15/abs/ic0506512.html}, eprint= {http://www.unige.ch/sciences/chifi/publis/refs_pdf/ref00630.pdf}, doi= {10.1021/ic0506512}, abstract = {{Visible pump-probe spectroscopy has been used to identify and characterize short-lived metal-to-metal charge transfer (MMCT) excited states in a group of cyano-bridged mixed-valence complexes of the formula [LCo$^{III}$NCM$^{II}$(CN)$_5$]$^{-}$, where L is a pentadentate macrocyclic pentaamine (L$^{14}$) or triamine-dithiaether (L$^{14S}$) and M is Fe or Ru. Nanosecond pump-probe spectroscopy on frozen solutions of [L$^{14}$Co$^{III}$NCFe$^{II}$(CN)$_5$]$^{-}$ and [L$^{14S}$Co$^{III}$NCFe$^{II}$(CN)$_5$]$^{-}$ at 11 K enabled the construction of difference transient absorption spectra that featured a rise in absorbance in the region of 350-400 nm consistent with the generation of the ferricyanide chromophore of the photoexcited complex. The MMCT excited state of the Ru analogue [L$^{14}$Co$^{III}$NCRu$^{II}$(CN)$_5$]$^{-}$ was too short-lived to allow its detection. Femtosecond pump-probe spectroscopy on aqueous solutions of [L$^{14}$Co$^{III}$NCFe$^{II}$(CN)$_5$]$^{-}$ and [L$^{14S}$Co$^{III}$NCFe$^{II}$(CN)$_5$]$^{-}$ at room temperature enabled the lifetimes of their Co$^{II}$-Fe$^{III}$ MMCT excited states to be determined as 0.8 and 1.3 ps, respectively.}}, year = {2005} }