Electrochemical and chemical syntheses,structures, and optical properties of the zinc and cadmium complexes in the N,N,O,S-ligand environment

The chemical and electrochemical syntheses of the zinc (I) and cadmium (II) complexes are carried out on the basis of the tridentate Schiff base (H₂L), the condensation product of (2-tosylaminoaniline) N-(2-aminophenyl)-4-methylbenzenesulfunamide with 1-phenyl-3-methyl-4-formylpyrazole-5-thiol. The structures and compositions of the synthesized metallochelates are proved by the data of C, H, and N elemental analyses, IR spectroscopy, and ¹H NMR spectroscopy. X-ray absorption spectroscopy is used to determine the structure of the zinc complex. The binuclear structure of the cadmium complex is confirmed by the X-ray diffraction data (CIF file CCDC no. 1471159). The optical properties of H₂L and the zinc and cadmium complexes in dimethyl sulfoxide (DMSO) solutions are studied.     

Crystal structure of bis-Isonicotinoyl hydrazone of 2,5-diformylpyrrole

bis-Isonicotinoyl hydrazone of 2,5-diformylpyrrole existing in the crystal in the form of a tetrahydrate of the hydrazone tautomeric form is synthesized and its structure is described. In the crystal, an infinite three-dimensional network of hydrogen bonds is formed by hydrazone molecules. The neighboring hydrazone molecules are bonded by intermolecular π stacking interactions. A quantum chemical calculation of the geometry and total energy of possible tautomers in vacuum and an aqueous solution is performed.     

Crystal Structure of Mono- and Trinuclear Ni(II) Complexes with Bis-Azomethine Based on 2-Amino-3-Formylpyridine

Russian Journal of Coordination Chemistry - The structure of a new mononuclear nickel(II) complex with bis-azomethine [Ni(H2L)]+ · CH3COO– · H2O, resulting from condensation of...     

Synthesis, structure, and complexing ability of hetarylhydrazones of glyoxylic acid

Benzoxazolyl-, benzthiazolyl-, 2′-quinolinyl- and 1′-phthalazinylhydrazones of glyoxylic acid (H₂L) and their complexes have been synthesized. The acid-base properties of the obtained hydrazones were studied by the methods of potentiometric titration and spectrophotometry. The hydrazones were shown to form mononuclear octahedral complexes M(HL)₂ with Ni(II) and Mn(II) acetates, whereas with Zn(II) and Cu(II) acetates binuclear complexes M₂L₂ were formed. The nature of the exchange interaction between the Cu(II) ions is discussed.     

Local surrounding of cobalt(II) in dithiocarbamate complexes,their magnetic and spectral properties

[Co(S₂CNRR’)₂] complexes [R = R’ = CH₃, C₂H₅, C₃H₇, C₄H₉, or CH₂C₆H₅; RR’ = (CH₂)₅, (CH₂)₆, or (CH₂)₂O(CH₂)₂] were prepared via interaction of CoCl₂ with sodium dithiocarbamates in aqueous medium (pH 6–7). [Co(S₂CNRR’)₂] are low-spin compounds (μ_eff 2.19–2.45 μ_B) with distorted square-planar geometry of the CoS₄ coordination node. The Co-S bonds length is 2.22–2.26 Å, and the distance between cobalt and carbon atoms is 2.73–2.74 Å.     

Assessing the Level of Compromise in Real Choice Models

We analyze the plurality runoff rule often used in national elections and prove that the corresponding choice function is Borda-rational. The compromise level attained in real voting systems is defined. The corresponding measures are calculated for the case of plurality runoff with three main candidates. We investigate the influence of the axiom of independence of irrelevant alternatives on the rationality type of choice functions realized in multicriterion choice systems.