Covalency in Actinide 5f Compounds:The ESCA Spectra of Diphthalocyaninato-Uranium (IV) and -Thorium(IV).

摘要

The nature of the bonding in both UPc2 and ThPc2 (Pc = phthalocyaninato ion) has been studied by x-ray photoelectron spectroscopy. While the ESCA spectrum of each of the U(4f) levels reveals two electron 'shake-up' satellites characteristic of 5f-orbital participation in bonding, i.e. covalency, the corresponding Th(4f) levels do not. The two 'shake-up' satellite photopeaks observed in the U(4f) spectra probably arise from electron charge-transfer from molecular orbitals of both metal and ligand character to the corresponding antibonding molecular orbitals. (Author)