EFFECT OF SUBSTITUENTS ON LIGANDS AND SOLVENTS ON THE ELECTRON DENSITY OF VANADIUM ATOMS IN VO (SALEN) COMPLEX COMPOUNDS

• Main Author: Fauzan Hamzah, Muh
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/47509
• Institution: Institut Teknologi Bandung

Salen oxovanadium complex, hereinafter referred to as [VO(salen)], is a complex compound used as a catalyst for several chemical reactions. In the catalysis process, the common redox pair formed in the [VO(salen)] complex is VIV / VV. Changes in the oxidation number of vanadium atoms involve changes in electron density so that to know its ability in the oxidation-reduction process can be studied regarding the electron density of the vanadium atom. Several factors can affect the electron density of vanadium atoms in the [VO(salen)] complex, including, substituents on ligands and solvent donor effect. Therefore, the aim of this study is to study the effect of substituents on ligands and solvents on electron densities on vanadium atoms in [VO(salen)] complexes. The study was conducted computationally using the ORCA application with the B97-D method and base set 6-31G (D). The electron density of vanadium atoms in the [VO (salen)] complex and its derivatives, namely [VO(salophen)] and [VO(salcyen)], can be compared through several parameters, including the bond length V=O, natural charge (NBO), and Gibbs energy change (?G). From the results of the comparison of these parameters, it was concluded that the substituents in salophen ligands reduce the electron density of vanadium atoms relative to salen ligands. Whereas the substituents in the salcyen ligand increase the electron density of the vanadium atom relative to the salen ligand. In addition, the presence of a solvent can increase the density of electrons in the complex in general. Solvents that have a higher dielectric constant can generally facilitate the transfer of electrons to vanadium atoms. Among these complex compounds, [VO(salcyen)] is greatly affected by the presence of solvents.