Electronic structure and nature of the metal-ligand chemical bond of Be, Mg, and Zn β-diketonates by quantum chemistry methods.

The electronic structure of Be (II), Mg (II), and Zn (II) acetylacetonates and hexafluoroacetylacetonates was calculated in the DFT approximation. The energies of MOs and ionization energies calculated by the OVGF method were compared with the published data of photoelectron spectroscopy (HeI). The outer valence region of the spectra is equally effectively reproduced by DFT and OVGF methods. The calculations allowed determining the ionization energies of the π 2 orbitals of the chelate cycles. It was determined that an increase in the binding energy of the electrons of the valence and core levels upon substitution of CH 3 >CF 3 by 1,7–2,1 eV was correlated with a change of the negative charge of the carbon atom of the substituted groups on positive one. The polarity of M − O bonds increases in the series of Be, Mg, Zn. It was found that in addition to outer valence orbitals, a covalent bonding was also significantly affected by the deep valence σ-orbital 4 a 1 with a high degree of overlap with metal s-orbitals. • The DFT and OVGF calculations were performed to determine the electronic structure of compounds. • The effect of CH 3 >CF 3 substitution on electronic structure has been studied. • Calculated geometry data and outer valence electronic structure were compared with experimental data. [ABSTRACT FROM AUTHOR]