XPS study of the electronic structure of heterometallic complexes Fe 2MO(Piv)6(HPiv)3 (M = Ni, Co)

Heterometallic complexes Fe2MO(Piv)6(HPiv) 3 (M = Ni, Co) have been studied by XPS. The complexes are identified as high-spin complexes with metal atoms in oxidation states M(II) and M(III). A change in the ligand environment of metal atoms has an effect on both the energetic state of metal atoms and the XPS pattern. The substitution of a Co atom for the nickel atom in the heterometallic complexes changes the XPS pattern of iron and their magnetic state. For the Fe2MO(Piv) 6(HPiv)3 complexes, quantum-chemical calculations have been performed at the density functional theory (DFT) level. In combination with XPS and magnetochemistry data, the quantum-chemical calculation demonstrates that the Fe, Ni, and Co atoms in the trinuclear complexes are in the high-spin local state and that the ground state is dominated by antiferromagnetic exchange interaction. © 2013 Pleiades Publishing, Ltd

XPS study of the electronic structure of heterometallic complexes Fe 2MO(Piv)6(HPiv)3 (M = Ni, Co)

Heterometallic complexes Fe2MO(Piv)6(HPiv) 3 (M = Ni, Co) have been studied by XPS. The complexes are identified as high-spin complexes with metal atoms in oxidation states M(II) and M(III). A change in the ligand environment of metal atoms has an effect on both the energetic state of metal atoms and the XPS pattern. The substitution of a Co atom for the nickel atom in the heterometallic complexes changes the XPS pattern of iron and their magnetic state. For the Fe2MO(Piv) 6(HPiv)3 complexes, quantum-chemical calculations have been performed at the density functional theory (DFT) level. In combination with XPS and magnetochemistry data, the quantum-chemical calculation demonstrates that the Fe, Ni, and Co atoms in the trinuclear complexes are in the high-spin local state and that the ground state is dominated by antiferromagnetic exchange interaction. © 2013 Pleiades Publishing, Ltd

XPS study of the electronic structure of heterometallic complexes [Fe 2MO(O2CCH3)6(H2O) 3] · 3H2O (M = Co, Ni)

Heterometallic compounds of general formula [Fe 2 III MIIO(O2CR)6(H2O)3] · 3H2O (R = CH3, M = Co, Ni; R = CCl3, M = Co, Ni) have been studied by XPS. The compounds have been identified as high-spin complexes with metal atoms in oxidation states M(II) and M(III). Analysis of the XPS data revealed the tendency of the XPS pattern and magnetic parameters of molecules to change with a change in the electronic nature of metal atoms. The assignment is based on the degree of covalence of the M-O bond. In chloro-substituted heterocomplexes, electron density delocalization on the metal atoms with metal-to-ligand charge transfer through three bonds (M-O-C-C) is observed. The substitution in terminal groups leads to the change in the electron density distribution between the carboxylate and terminal groups. © 2014 Pleiades Publishing, Ltd

XPS study of the electronic structure of heterometallic complexes [Fe 2MO(O2CCH3)6(H2O) 3] · 3H2O (M = Co, Ni)

Heterometallic compounds of general formula [Fe 2 III MIIO(O2CR)6(H2O)3] · 3H2O (R = CH3, M = Co, Ni; R = CCl3, M = Co, Ni) have been studied by XPS. The compounds have been identified as high-spin complexes with metal atoms in oxidation states M(II) and M(III). Analysis of the XPS data revealed the tendency of the XPS pattern and magnetic parameters of molecules to change with a change in the electronic nature of metal atoms. The assignment is based on the degree of covalence of the M-O bond. In chloro-substituted heterocomplexes, electron density delocalization on the metal atoms with metal-to-ligand charge transfer through three bonds (M-O-C-C) is observed. The substitution in terminal groups leads to the change in the electron density distribution between the carboxylate and terminal groups. © 2014 Pleiades Publishing, Ltd

Theoretical and experimental study of the coordination ability of 4,6-dimethylpyrimidinylhydrazone diacetylmonooxime towards Ni(ii), Mn(ii), Fe(iii) and Co(iii) ions

The ligand system diacethylmonooxime 4,6-dimethylpyrimidylhydrazone and its Ni(ii), Mn(ii), Fe(iii) and Co(iii) complexes with composition [Ni(H2L)2]Cl2·1.17H2O, [Mn(H2L)2](ClO4)2·0.75H2O, [Fe(H2L)2]·3Cl·H2O and [Co(HL)2]·ClO4 have been synthesized. The structure of both the ligand and complexes has been established through IR and 1H NMR spectroscopy, magnetic measurements and X-ray analysis. The acid-base properties of the hetarylhydrazone were studied with potentiometric and spectrophotometric methods. The protolytic equilibrium constants and energies of possible ligand tautomeric forms have been obtained with these data and from quantum-chemical calculations. These calculated pKa values are compared to the computational data. The structures of the hetarylhydrazone and its Ni(ii), Mn(ii) and Co(iii) complexes have been also determined by X-ray analysis. It was shown that the high-spin Ni(ii), Mn(ii), and Fe(iii) complexes possess a distorted-octahedral structure of the coordination unit. The low-spin Co3+ complex has been synthesized by the reaction between Co(ClO4)2 and the hetarylhydrazone, the ligand being reacted in the monodeprotonated pyrimidine tautomeric form. This diacethylmonooxime 4,6-dimethylpyrimidylhydrazone ligand shows potential in stabilizing different metal complexes with interesting reactivity, magnetic and electrochemical properties. This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique

Anion mediated switching from mono- to polymer structure in copper(II) complexes with 4,6-dimethylpyrimidinylhydrazone 1-phenyl-3-methyl-4-formylpyrazol-5-one

The novel hetarylhydrazone (H2L) has been synthesized by condensation of 2-hydrazino-4,6-dimethylpyrimidine with 1-phenyl-3-methyl-4-formylpyrazol-5-one and its complexes with CuCl2 and Cu(ClO4)2 have been obtained. The structures of the compounds were studied by means of NMR, IR, ESR spectroscopy, magnetic susceptibility measurements and X-Ray diffraction methods. The quantum-chemical modelling of the geometry and electronic structure of the hetarylhydrazone's tautomers has been carried out. The influence of the nature of acido-ligand on the structure of complex compounds has been established. Copper(II) chloride gives mono-nuclear complex [Cu(H2L)Cl2].H2O, while copper(II) perchlorate yields the polymeric structure ([Cu(HL)(CH3OH)]ClO4)n. For polymer compound no magnetic exchange interactions were detected. © 2019 Elsevier B.V