UV Spectra of Tris(2,2′-bipyridine)–M(II) Complex Ions in Vacuo (M = Mn, Fe, Co, Ni, Cu, Zn)

We present electronic spectra in the π–π* region of a series of tris(bpy)–M(II) complex ions (bpy = 2,2′-bipyridine; M = Mn, Fe, Co, Ni, Cu, Zn) in vacuo for the first time. By applying photodissociation spectroscopy to cryogenically cooled and mass selected [MII(bpy)3]2+ions, we obtain the intrinsic spectra of these ions at low temperature without perturbation by solvent interaction or crystal lattice shifts. This allows spectroscopic analysis of these complex ions in greater detail than possible in the condensed phase. We interpret our experimental data by comparison with time-dependent density functional theory.