Unveiling the electronic structure of coordination compounds: A density functional theory study.

For decades, coordination compounds have strongly demonstrated their importance in many daily disciplines and industries. Their applications include catalysts, magnetic materials, porous materials, biomedical applications, drug delivery, etc. Coordination compounds are also highly present in stereochemistry as chiral luminescent materials, homochiral, chiral liquid crystals, enantioselective sensors, chiroptical switches, and magnetochiral compounds. For all these reasons and many more, tremendous effort has been devoted to the study of coordination compounds experimentally and theoretically. The development of new potential theoretical approaches has made it fruitful to study these kinds of compounds. In this contribution, a theoretical DFT-based study is performed on complexes of an organic ligand with different metal ions in order to reveal the energetics of such reactions. First of all, the electronic structure of the studied ligand as well as the formed complex was optimized at DFT//B3LYP/6-31G(d) level of theory. Then, using various approaches such as Fukui functions, and based on the obtained optimized structure of the studied complexes at the level of B3LYP/6-31G(d), the possible sites responsible for chelation with the metal ions were determined. Finally, the energetics based on thermodynamic quantities calculations, such as enthalpy, were also investigated in order to predict the stability and thermochemistry of the studied coordination compounds. It was found that the stability and the structure of the complexes not only depend on the ligand but also on the nature of the metal ion.