Vol 44, No 10 (2018)

Nanostructured catalysts were synthesized by deposition of cobalt selenide and telluride on highly dispersed carbon black from solutions of corresponding metal chalcogenide clusters. The catalysts were characterized by powder X-ray diffraction, energy dispersive X-ray spectroscopy, and scanning electron microscopy. The electroreduction of oxygen at these catalysts is accompanied by consumption of four electrons. The catalysts were shown to be tolerant to methanol.

The chemisorption binding of gold(III) by freshly precipitated binuclear zinc dithiocarbamates [Zn₂(S₂CNR₂)₄] from solutions in 2 M HCl makes it possible to obtain heteroligand complexes [Au(S₂CNR₂)Cl₂]: R = CH₃ (I), iso-C₃H₇ (II); R₂ = (CH₂)₆ (III). The structural organization of complexes I, II, and III is determined by X-ray diffraction analysis (CIF files CCDC no. 1813107, 1813369, and 1813108, respectively). The distorted square–planar structure of the cis-[AuS₂Cl₂] chromophores shows the low-spin dsp²-hybrid state of the central gold atom. Pairwise secondary interactions Au⋅⋅⋅S between the adjacent molecules in complexes I and III result in the building of zigzag polymer chains (⋅⋅⋅[Au{S₂CN(CH₃)₂}Cl₂]⋅⋅⋅)_n and binuclear aggregates [Au{S₂CN(CH₂)₆}Cl₂]₂ at the supramolecular level. Complex II is presented by discrete molecules [Au{S₂CN(iso-C₃H₇)₂}Cl₂]. According to the simultaneous thermal analysis data, the single final product of the thermolysis of compounds I–III is reduced elemental gold.

The compositions and structures of the products of the reaction of TaF₅ with Ph₂P(O)(CH₂)₂C(O)NМе₂ (L) in СН₃СN and СН₂Сl₂ are studied by the ¹⁹F and ³¹Р NMR methods. As the hydrocarbon bridge between the Р=О and С=О donor groups in carbamoylphosphine oxides elongates from –СН₂– to (–СН₂–)₂, the chelation ability of the ligand is retained and the composition of the complexes formed in a solution is determined by the ratio of components. The compositions and structures of the hydrolysis products are studied. Distinctions in the coordination behavior of the considered ligand during complex formation with tantalum pentafluoride and titanium tetrafluoride are studied.

The reactions of tris(3-fluorophenyl)antimony (3-FС₆H₄)₃Sb with 3,5-dinitrobenzoic, bromoacetic, chloroacetic, and cinnamic acids in the presence of tert-butyl hydroperoxide afford tris(3-fluorophenyl)antimony bis(3,5-dinitrobenzoate (I), tris(3-fluorophenyl)antimony bis(bromoacetate (II), tris(3-fluorophenyl)antimony bis(chloroacetate) (III), and tris(3-fluorophenyl)antimony dicinnamate (IV). According to the X-ray diffraction data, the coordination mode of the Sb atoms in all compounds is a trigonal bipyramid (CIF files CCDC nos. 1576022 (I), 1576023 (II), 1575287 (III), and 1576967 (IV). The axial angles OSbO are 174.70(6)°, 175.92(15)°, 176.62(6)°, and 175.81(11)°. The Sb−O and Sb−С bond lengths are 2.117(2), 2.137(2), and 2.105(3)−2.119(2) Å in I; 2.110(4), 2.129(4), and 2.096(5)−2.112(5) Å in II; 2.118(2), 2.136(2), and 2.120(2)−2.128(2) Å in III; and 2.142(3) and 2.115(3)−2.119(4) Å in IV. The Sb⋅⋅⋅O intramolecular distances with the carbonyl oxygen atom (2.895(3), 2.968(4) Å (I); 2.814(6), 2.930(6) Å (II); 2.809(3), 2.933(4) Å (III); and 2.601(4) Å (IV)) are shorter than the sum of the van der Waals radii of Sb and O by ∼1.0 Å.