Quantum Chemical Simulation of Hexa-, Penta-, and Tetracoordination Modes in Stereoisomers of the Co(II) and Ni(II) Bis(ligand) Complexes Based on (N,O,S(Se))-Tridentate Azomethines

Russian Journal of Coordination Chemistry - The molecular structures and relative energies of hexa-, penta-, and tetracoordinated stereoisomers of the Co(II) and Ni(II) bis(ligand) complexes based...     

Possibilities of tetra-, penta-, and hexacoordination in quantum-chemical simulation of mechanism of formation and stereoisomerization of bisligand azomethine complexes of Zn(II), Cd(II), and Hg(II)

The competition between tetra-, penta-, and hexacoordination with the MN₂O₂, MN₂O₂X, and MN₂O₂X₂ (X = S, Se) coordination nodes, respectively, during the formation of bisligand Zn(II), Cd(II), and Hg(II) complexes with bi- and tridentate heterocyclic azomethines has been studied by means of quantumchemical DFT simulation of the complex formation and further stereoisomerization. It has been found that pentacoordination was favorable for the Cd(II) and Hg(II) complexes, whereas the Zn(II) complexes are tetracoordinate.     

Cobalt(ɪɪ) and nickel(ɪɪ) bis(chelate) complexes with (N,O, O)-tridentate azomethine ligands: a quantum chemical study of stereoisomers with hexa-, penta-, and tetracoordinate central atoms

Russian Chemical Bulletin - The molecular structures and relative energies of stereoisomers of the Co?? and Ni?? bis(chelate) complexes composed of hexa-, penta-, or...     

Azomethine imines of pyrazolidone series and their bis-chelate Ni(II), Zn(II), Cd(II) complexes. Quantum chemical simulation

Prototropic processes in the molecules of azomethine imines with 2-pyrrolylmethylidene fragment were studied by the density functional theory (DFT) method and the most stable by energy isomers with the intramolecular hydrogen bond between the nitrogen atoms of the pyrrole and the pyrazole rings were found. The energy barriers of the reactions of intramolecular proton transfer were estimated. Based on quantum chemical calculations of the molecular structure of azomethine imine bis-chelates ML₂ [M = Ni(II), Zn(II), Cd(II)] with the coordination unit MN₂N₂ the most stable configurations of the complexes were determined.     

Quantum-Chemical Simulation of Tetra-, Penta-, and Hexacoordinated Stereoisomers of Bis-Ligand Ni(II) Complexes based on Polydentate Heterocyclic Derivatives of Azomethines

Molecular structures and relative energies of tetra-, penta-, and hexacoordinated stereoisomers of bis-ligand Ni(II) complexes based on polydentate heterocyclic derivatives of azomethines [coordination nodes of isomers NiN₂O₂, NiN₂O₂Y, NiN₂O₂Y₂ (Y = S, Se)] were calculated using density functional theory. Within the framework of the proposed quantum chemical model of the mechanism of formation of NiL₂ complexes (taking into account the possibility of subsequent stereoisomerization) the most probable product of complex formation was found to be the isomer with pentacoordinated central metal atom and nonequivalent ligands, tridentate and bidentate.