Electronic Structures of Copper(I) and Silver(I) beta-Diketonate Complexes

The valence electronic structures of [Cu(hfac)L] (hfac = CF(3)C(O)CHC(O)CF(3); L = PMe(3), CNMe), [Ag(hfac)(PMe(3))], and [Ag(fod)(PEt(3))] (fod = t-BuC(O)CHC(O)C(3)F(7)) have been studied by recording their photoelectron spectra and by performing Xalpha-SW calculations on the model compounds [M(dfm)(PH(3))] (dfm = HC(O)CHC(O)H; M = Cu, Ag) and [Cu(dfm)(CNH)]. For the copper complexes, the spectra were recorded between 21 and 160 eV using He I, He II and synchrotron radiation; while, for the silver complexes, He I and He II, spectra were recorded. Assignments were made by comparison of experimental and calculated values of band energies, and, for the copper complexes, by similar comparison of experimental and theoretical branching ratios as a function of photon energy. For the silver complexes, a more limited comparison of band intensities in the He I and He II spectra was made. In analogous compounds, it is shown that the binding energies follow the sequence Ag 4d > Cu 3d, with an energy difference of almost 2 eV.