Effects of pivalate ligand substitutions on the electronic properties of chromium-wheels host complexes; A molecular modelling study.

Document Type : Original Article

Author

• motahare sadeghi googheri

Islamic Azad University of Sirjan

Abstract

In this study, the effect of substitution of pivalate ligands with halogenated X-tBuCO2 and X-iPrCO2 ligands, (where X represents F, Cl, Br and I halogens) on the electronic properties of binuclear chromium (III) model ([Cr2F(tBuCO2)2(H2O)2(OH)4]-1) were evaluated by density functional theory (DFT) methods. For this purpose, two complexes of [Cr2F(X-tBuCO2)2(H2O)2(OH)4]-1 and [Cr2F(X-iPrCO2)2(H2O)2(OH)4]-1 complexes were designed that in the first type, one of methyl groups were halogenated, namely one of its hydrogens were replaced with halogen atom (3-Halogeno-2,2-dimethylpropanoate) while in the second type, one of the methyl groups was entirely substituted with the halogen atom (2- Halogeno-2-methylpropanoate). Results showed that in X-tBuCO2 and X-iPrCO2 anionic ligands, for AFM complexes increased energy band gap of
the complex by going from F- to I- ions but substitution by Br-iPrCO2-containing decreased it and for FM complexes the replacement of fluorine pivalate ligand by with halogen anions (Br- and I-) decreased energy band gap of the complexes but only in the case of α- spin Cl-iPrCO2-containing increased it.Also Total density of state (TDOS) and Partial density of state (PDOS) for complexes were calculated

Keywords

• DFT
• Halogenation effect
• Border orbitals
• DOS
• Molecular nanomagnets

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