Ternary Oxovanadium(IV) Complexes Based on Lawsone: Synthesis, Spectroscopic Characterization, and DFT Studies
Huda A. Hadi, Roaa S. Awad Al‐Luhaibi, Eiman T. Alshammary, Taysser T. Ahmad, Ahmed M. Ibrahim, Othman I. AlajrawyABSTRACT
Four novel vanadium(IV) complexes have been synthesized by mixing the bioactive chemical Lawsone (2‐hydroxy 1,4‐naphthoquinone) with other secondary ligands. The complexes were characterized using different spectroscopic techniques such as FTIR, UV–vis, mass spectroscopy, CHN analyses, magnetic susceptibility, electrical conductivity, and theoretical calculations. The suggested chemical formulae of the complexes are [VO(Law)(L 1 )]·H 2 O, [VO(Law)(L 2 )]·3/2H 2 O, and [VO(Law)(L 3 )]·7/2H 2 O and [VO(Law)(L 4 )]·2H 2 O, where (Law) is 2‐hydroxy‐1,4‐naphthoquinone, (L 1 ) is 8‐hydroxyquinoline, (L 2 ) is 3,4‐diaminobenzoic acid, (L 3 ) is o ‐phenyldiamine, and (L 4 ) is dithiooximide. The FTIR spectra showed how the ligands binding with the vanadyl core (VO) 2+ ion. The UV–vis spectra displayed electronic transitions. The mass spectra verified the mononuclear identity for the prepared complexes. The DFT calculations support the experimental findings about the suggested geometry of the complexes as distorted square pyramidal with a vacant sixth position. The DFT calculation of ligands and the complexes gave as the bond lengths and bond angles with the clear view of the values for both HOMO and LUMO orbitals. These findings about the prepared complexes with their distorted square pyramidal geometry will provide a basis for the future studies with different bioactive ligands to them in different applications (specify application). The molar ratio for complex formation was 1:1:1 (M: Law: L).