TITLE:
Structural, Spectral (IR and UV/Visible) and Thermodynamic Properties of Some 3d Transition Metal(II) Chloride Complexes of Glyoxime and Its Derivatives: A DFT and TD-DFT Study
AUTHORS:
Ludovid Ngouo Nogheu, Julius Numbonui Ghogomu, Desire Bikele Mama, Nyiang Kennet Nkungli, Elie Younang, Shridhar Ramachandra Gadre
KEYWORDS:
Glyoxime Complexes, DFT, Binding Energy, Electronic Absorption
JOURNAL NAME:
Computational Chemistry,
Vol.4 No.4,
October
25,
2016
ABSTRACT: Metal complexes bearing vic-dioxime ligands have been extensively used as analytical
and biochemical reagents, and are well-known antimicrobial agents. Herein is reported
a DFT study on the molecular structures, thermodynamic properties, chemical
reactivity and spectral properties of some 3d metal(II) chloride complexes of
glyoxime. The functionals B3LYP and CAM-B3LYP have each been used in conjunction
with LANL2DZ for the metal(II) ions (Fe2+, Co2+, Ni2+ and Cu2+) and the Poplestyle
basis set 6-31G+(d,p) for the rest of the elements, to perform theoretical calculations.
The metal complexation abilities of the glyoxime ligands studied in this work
have been evaluated on the basis of metal-ligand binding energies. These ligands
were found to have high affinities towards Ni(II) and Fe(II) ions, and all complexation
reactions were found to be thermodynamically feasible. Ligand-to-metal electron
donations in the complexes studied have been revealed by natural population
analysis. The fully optimized geometries of the complexes have adopted square planar
structures around the central metal ions. On the basis of orbital composition
analysis, the UV-Vis electronic absorption bands of these molecules have been attributed
mainly to MLCT, LMCT and d-d electronic transitions involving metal-based
orbitals.