By applying density functional theory (DFT), the relationships between the electron structures and the complexation of the two types of bis-β-diketone ligands (dithiol-γ-linked or alkyl-γ-linked) were investigated, based on the polarized continuum model (PCM) of the self-consistent reaction field (SCRF). Using the model B3LYP/6-31G**, the geometries of the ligands were optimized and the electron structure changes calculated. The calculation results, in comparison with the crystal data of the complexes, indicated that there were clear correlativity and consistency of the geometries, frontier orbitals, dipole moments and net charges of the ligands with the geometries, active atoms, and forms (mono- or poly-nuclear, inter- or intra-molecular) of the complexes. It is therefore demonstrated that the theoretical calculations of ligands can provide a reasonable analysis and prediction for the geometries and complexation of complexes.

Key words: bis-β-diketone ligand, complexation, density functional theory, electron structure