Electronic structure of 1,5-cyclooctadiene-copper(I)-hexafluoroacetylacetonate

The valence electronic structure of the compound 1,5-cyclooctadiene-copper( I)-hexafluoroacetylacetonate [(1,5-COD)Cu(hfac)], a prospective precursor f or creation of thin copper films for microelectronics, has been investigate d by ultraviolet photoelectron (He I) and X-ray emission spectroscopy. Elec tronic interactions of the 1,5-COD li-and with the copper atom were reveale d by comparing spectra of the complex and of free 1,5-COD. C K alpha spectr a indicated a significant decrease of pi electron density in the double bon ds of 1,5-COD with the coordination of this molecule to the copper atom. Th e spectral changes and features were interpreted using the results of densi ty functional calculation on the molecules. The detailed analysis of the hi ghest occupied molecular orbitals of (1,5-COD)Cu(hfac) was carried out to e xplain the relatively low values of first ionization potential and decompos ition temperature for the complex.