Journal of Electron Spectroscopy and Related Phenomena. 60 (1992) 211-223 zyxwvutsrqponmlkjihg Elsevier Science Publishers B.V., Amsterdam * 211 Electronic structure of some copper(I1) and iron(III) /?-diketonates Oleg L. Shcheka and Vitalii I. Vovna Laboratory of Electron Spectroscopy, Physical and Technical Institute, Far Eastern State University, 25 Uborevitcha Str., Vladivostok 690600 (Russian Federation) (Received 8 January 1992; accepted 15 April 1992) Abstract The electronic structure of the CuL, (L = acac, dpm) and FeL, (L = acac, tfa, dpm, dbm) complexes was investigated by using ultraviolet photoelectron spectroscopy and X-ray emission spectroscopy of the vapours. The experimental data (ionization potentials, atomic populations of valent occupied molecular orbitals, and transition energies between valent and core orbitals) were compared with the results of theoretical calculations (CNDO/B method), The sufficiently good agreement between the theoretical and experimental data allowed the accurate determination of the important regularities in the electronic structure of the chelate cycles of different complexes and the character of the M-L chemical bond. INTRODUCTION The description of the electronic structure of copper and iron(II1) P-diketonates has been the object of some past investigations [l-73. The ionization potentials (IPs) of copper bis-chelate valent molecular orbitals (MOs) have been determined by means of photoelectron (PE) spectroscopy [l-4], and the atomic populations of these orbitals have been found using X-ray emission (XE) spectroscopy [3]. The XE spectroscopic analysis of FeL, (L = acac, dpm, dbm) vapours has been reported [5] and these data have been compared with the PE spectra of iron(II1) /?-diketonates [6,7] in order to determine the character of the Fe-L chemical bond. Analysis of PE spectroscopic data allows the determination of the energy positions of valent occupied MOs, whilst the XE spectroscopic zyxwvutsrqponmlkjihgf data allows us to obtain information on the atomic population of the orbitals. Obtaining XE spectra of heavy complexes in the vapour phase is very difficult (XE Correspondence to: O.L. Shcheka, Laboratory of Electron Spectroscopy, Physical and Techni- cal Institute, Far Eastern State University, 25 Uborevitcha Str., Vladivostok 690600, Russian Federation. 0368-2048/92/$05.00 0 1992 Elsevier Science Publishers B.V. All rights reserved.