O. Yu. Korshunov

Synthesis, structures, and spectral properties of biomimetic azomethine metal chelates with chromophores CuN2S2, CuN2O2, and CuN2Se2. Crystal structure of bis[4-(benzyl)aldimino-3-methyl-1-phenyl-5-pyrazolothiolato]copper(II)

Copper(II) chelates of composition CuL2 were synthesized based on 4-aminomethylene derivatives of 5-thiopyrazoles (LH). The complexes were studied by UV, IR, ESR, and EXAFS spectroscopy, magnetochemistry, and X-ray diffraction analysis. The coordination polyhedra in the complexes are pseudotetrahedra or octahedra of the types CuN2S2 or CuN4S2, respectively, which are distorted due to the Jahn—Teller effect. The UV and ESR spectra of copper chelates with a six-coordinate metallocycle formed by the N and S atoms of the azomethine ligand and the nitrogen atom of the quinoline substituent (R) of the C=N−R fragment are most similar to the spectra observed for metals involved in the active centers of natural metalloenzymes (“blue” copper proteins).

Synthesis and IR and NMR spectroscopic studies of amino derivatives of oxo-, thio-, and selenopyrazole. Crystal and molecular structure of 1-phenyl-3-methyl-4-methylene-(N-8-aminoquinoline)-5-oxopyrazole

Three compounds of the pyrazole series—o-oxo, thio, and seleno derivatives—have been synthesized and characterized by IR and NMR spectroscopy. The crystal structure of the oxo derivative is determined (Syntex P21 diffractometer, MoKα radiation, graphite monochromator, θ/2θ scan mode, 2θmax = 57°, direct method, anisotropic—isotropic (H) least-squares refinement for 2015 reflections, R = 0.043, wR2 = 0.1084). The crystals are monoclinic, a = 7.543(1) Å, b = 7.850(2) Å, c = 27.909(6) Å, β = 93.79(3)°, Z = 2, and space group P21/c. It is found that the o-hydroxyazomethine derivatives of the pyrazolone series exist in the crystal as 4-aminomethylene-5-oxo tautomers. The proton is localized at the exocyclic N atom. It lies in the plane of the main molecular fragment and participates in the intramolecular bifurcate N—H⋯O(N) hydrogen bond, which closes the six-membered and five-membered H-rings, respectively.

Metal complexes of 2-hetarylindandiones-1,3

The chelate and molecular complexes of 2-(2-benzazolyl, perimidyl)-indandiones-1,3 were synthesized for the first time. The structures of the ligands (tautomeric forms) and complex compounds were determined from the X-ray diffraction, 1H, 13C NMR, and IR data and the quantum-chemical calculations (RHF SCF in 6-31 G** basis).

METAL CHELATES OF NEW LIGANDS: 1,2-BENZOTHIAZINE-1,1-DIOXIDE DERIVATIVES

Abstract The novel chelates ML2 (M = Co, Ni, Cu, Zn) were obtained by the interaction of 3-benzoyl-4-hydroxy-1,2-benzothiazine-4(3H)-on-1,1-dioxide and 2-methyl-3-benzoyl-4-hydroxy-1,2-benzo-thiazine-4(3H)-on-1,1-dioxide with elemental metals (direct electrochemical synthesis) or their acetates (chemical synthesis) in methanol. The tetrahedral or polymeric-octahedral structures with a β-diketonate fragment are assigned based on IR and 1H NMR spectra. The studied ligands and their complexes are model compounds of molecules used as anti-inflammatory drugs.

2-(2-pyridyl)-3-thioindan-1-one: Synthesis, tautomerism, and complexing properties

Chelate and molecular complexes of 2-(2-pyridyl)-3-thioindan-1-one were prepared. The structure of the ligand (prevalent tautomeric form), including the coordination mode, was proved by 1H NMR, IR, and EXAFS spectroscopy and by quantum-chemical calculations. The soft-hard properties of the ligand were demonstrated.

New metal chelates of 5-amino-4-azopyrazoles: The crystal and molecular structure of bis{1-phenyl-3-methyl-4-(p-tolyl)azo-5-(p-carboxymethoxyphenyl)pyrazolamidato}copper(II)

The reactions of 1,3-alkyl(aryl) derivatives of 5-amino-4-azopyrazoles (HL) with copper(2+) acetate afford metal chelates CuL2. Complexes with the CuN4 chromophore containing a substituted amino group (X = NR) as a donor, like their azomethine analogues, have a pseudotetrahedral structure. Copper chelates with X = NH are planar. The X-ray diffraction data and an additional hyperfine structure (ahfs) from 15N atoms of the azo group in the labeled complexes provide evidence for the formation of six-membered metallocycles. The coordination polyhedron in bis{1-phenyl-3-methyl-4-(p-tolyl)azo-5-(p-carboxymethoxyphenyl)pyrazolamidato}Cu(II) can be described as a pseudotetrahedron.

2-(2-Pyridyl)indandione-1,3 and Its Zinc(II) and Nickel(II) Complexes: Synthesis and Physicochemical Characterization

Inner complex compounds (ICCs) and molecular adducts based on 2-(2-pyridyl)indandione-1,3 have been synthesized for the first time. The structure of the ligand (the preferred tautomer) and the complexes has been studied using X-ray crystallography, 1H NMR spectroscopy, and IR spectroscopy.

Metal Complexes with Novel Ambidentate Ligands: β-Enaminovinylketones with Annelated 1,2-Benzothiazine-1,1-Dioxide Fragment and Antipyrine Substituent

The data on competitive binding of ligands in metal complexes with ambidentate ligands (Schiff bases and β-aminovinylketones) were summarized. Special attention is given to chemical and electrochemical syntheses and structural study of novel chelates of heterocyclic enaminoketones with antipyrine substituent that form tetrahedral (Cu2+, Zn2+) or octahedral (Co2+, Ni2+) structures.

Synthesis, Physicochemical Properties, and Structure of Heterocyclic β-Aminovinyl Ketones and Related Copper(II) Complex

AbstractHeterocyclic β-aminovinyl ketones (HL) and the copper complex CuL2 are synthesized and studied by IR and 1H NMR spectroscopies. The crystal structure of one of the tautomeric HL molecules is determined by X-ray diffraction analysis. The crystals are triclinic: a = 9.261(6) Å, b = 9.448(6) Å, c = 11.310(5) Å, α = 96.74(5)°, β = 99.46(5)°, γ = 93.60(5)°, space group P