I. V. Korol’kov

Study of nitrosation of hexaammineruthenium(II): Crystal structure of trans-[RuNO(NH3)4Cl]Cl2

The nitrosation of [Ru(NH3)6]2+ in hydrochloric acid and alkaline ammonia media has been studied; the patterns of interconversion of ruthenium complexes in reaction solutions have been proposed. In both cases, nitrogen(II) oxide acts as the nitrosation agent. The procedure for the synthesis of [Ru(NO)(NH3)5]Cl3 · H2O (yield 75–80%), the main nitrosation product of [Ru(NH3)6]2+, has been optimized. Thermolysis of [Ru(NO)(NH3)5]Cl3 · H2O in a helium atmosphere has been studied; the intermediates have been identified. One of these products is polyamidodichloronitrosoruthenium(II) whose subsequent decomposition gives an equimolar mixture of ruthenium metal and dioxide. The structure of trans-[RuNO(NH3)4Cl]Cl2, formed in the second stage of thermolysis and as a by-product in the nitrosation of [Ru(NH3)6]Cl2, has been determined by X-ray diffraction.

Synthesis and luminescent properties of the complexes EuL(i-Bu2PS2)2(NO3) (L = Phen, 2,2′-Bipy, 4,4′-Bipy)

The mixed ligand coordination compounds EuL(i-Bu2PS2)2(NO3) (L = Phen, 2,2′-Bipy, 4,4′-Bipy) are synthesized. On the basis of X-ray analysis and IR spectra their structures are elucidated. The complexes containing Phen or 2,2′-Bipy are found to possess photoluminescent property.

Structure of [Dy(Phen)(C4H8NCS2)3]·3CH2Cl2 solvate. Magnetic properties and photoluminiscence of [Ln(Phen)(C4H8NCS2)3] (Ln = Sm, Eu, Tb, Dy, Tm) complexes

It is found that diffraction patterns of complexes I–V of the composition [Ln(Phen)(C4H8NCS2)3] (Ln = Sm, Eu, Tb, Dy, and Tm respectively) are similar. Single crystals of [Dy(Phen)(C4H8NCS2)3]·3CH2Cl2 (VI) obtained are. According to the X-ray crystallographic data, in the structure of VI the unit cell contains two crystallographically independent molecules of the [Dy(Phen)(C4H8NCS2)3] complex and six CH2Cl2 molecules. The N2S6 coordination polyhedron of the Dy atom is a distorted square antiprism. In the range of 2–300 K the magnetic properties of complexes I–V are studied. It is found that complex III passes to the magnetically ordered state; the spontaneous magnetization at 2 K is 24 600 G·cm3/mol. At 300 K compounds I–IV exhibit photoluminescence in the visible spectral range. It is found that the photoluminescence intensity of complex I is several times higher than the photoluminescence intensity of complexes II–IV.

Synthesis of the nanostructured luminophor Y2O3-Eu-Bi by the sol-gel method

The sol-gel method of the formation of the nanostructured luminophor based on Y2O3 doped by Eu3+ and Bi3+ was studied. The mechanism of the dehydration and dehydroxylation of gels and xerogels of the mixed hydroxides, particle sizes, structure, and luminescent properties of the synthesized products based on Y2O3 depend on the chemical nature of a precipitating agent (NaOH or NH4OH) and a washing agent (water and alcohol).

Syntheses and structures of p-HOOCC6F4COOH · H2O (H2L · H2O) and luminescent coordination polymers [Tb2(H2O)4(L)3 · 2H2O]n and Tb2(Phen)2(L)3 · 2H2O

Compounds p-HOOCC6F4COOH · H2O (H2L · H2O), [Tb2(H2O)4(L)3 · 2H2O]n (I), and Tb2(Phen)2(L)3 · 2H2O (II) are synthesized. According to the X-ray structure analysis data, the crystal structure of H2L · H2O is built of centrosymmetric molecules H2L and molecules of water of crystallization. The crystal structure of compound I is built of layers of coordination 2D polymer [Tb2(H2O)4(L)3]n and molecules of water of crystallization. The ligands are the L2− anions performing both the tetradentate bridging and pentadentate bridging-chelating functions. The coordination polyhedron TbO9 is a distorted three-capped trigonal prism. Acid H2L manifests photoluminescence in the UV region (λmax = 368 nm). Compounds I and II have the green luminescence characteristic of the Tb3+ ions, and the band with λmax = 545 nm (transition 5D4→ 7F5) is maximum in intensity. The photoluminescence intensity of compound II is higher than that for compound I.

Maleates of Mn(II), Fe(II), Co(II), and Ni(II) as precursors for synthesis of metal-polymer composites

Comparison was made for the structural, IR spectral, and thermoanalytical characteristics of normal [M1(H2O)2(C4H2O4)](H2O) (M1 = Co(II) and Ni(II)) and acid maleates [M2(H2O)4(C4H3O4)2] (M2 = Mn(II), Fe(II), Co(II) and Ni(II)). Only structures of acid maleates contain intramolecular asymmetric hydrogen bond whose asymmetry increases in the series of transition metal salts. Thermal decomposition of Co(II), Ni(II) normal maleates, and Mn(II), Fe(II), Co(II), Ni(II) acid maleates proceeds in three stages. Onset decomposition temperatures for the first and second stages decreases in the series of normal maleates Co(II) ≥ Ni(II) and increases in the series of acid maleates Fe(II) < Co(II) < Ni(II) ≈ Mn(II). Onset temperature of the third stage decreases in the series of both normal maleates Co(II) > Ni(II) and acid maleates Mn(II) > Fe(II) > Co(II) > Ni(II).

Synthesis, properties, and thermal decomposition products of [Ru(NH3)5Cl][PtCl6] and [Ru(NH3)5Cl]2[PtCl6]Cl2

The double complex salts [Ru(NH3)5Cl][PtCl6] (I) and [Ru(NH3)5Cl]2[PtCl6]Cl2 (II) were synthesized and studied by X-ray diffraction. They were found to be isostructural to the previously synthesized [Rh(NH3)5Cl][OsCl6] and [Ir(NH3)5Cl]2[PtCl6]Cl2. The thermolysis of the complexes in the atmosphere of hydrogen and helium was studied by the powder X-ray diffraction analysis. The product of the salt I thermolysis is a single-phase solid solution Ru0.5Pt0.5 (a = 3.857(3) Å), the thermolysis of salt II results in a double-phase metallic powder.

Study of the structure of a new heterometallic complex based on copper(II) ketoiminate [ cis -Cu(ki) 2 ·Pb(hfa) 2 ] 2

The cocrystallization method is used to obtain a new volatile heterometallic complex of the composition [Cu(ki)2·Pb(hfa)2]2, where ki = 2-iminopentan-4-onate and hfa = hexafluoroacetylacetonate. The crystallographic data for C20H18CuF12N2O6Pb: a = 10.6729(5)Å, b = 10.7712(5)Å., c = 13.4779(5)Å.; α = 79.1020(10)°, β = 84.5140(10)°, γ = 66.2470(10)°, P-1 space group, Z = 2, dx = 2.102 g/cm3. The compound has a molecular structure built of individual Cu...Pb...Pb...Cu-type tetramers. The Cu...Pb and Pb...Pb distances in the tetramer are 3.454. and 4.122. respectively; the Cu-Pb-Pb angle is 160.7°.

Synthesis of nanostructured nickel oxide

The process of formation of nickel oxide nanostructured powders by annealing nickel hydroxide in the temperature range 200–700°C was studied. Nickel hydroxide was prepared by precipitation with alkali from nickel nitrate solutions. The annealing process was shown to be multi-step. In the first stage the hydrogel Ni (OH)2·nH2O decomposes and partial dehydration of hydroxide occurs. Sizes of the formed particles decrease. At the temperatures above 230°C, further hydrogel decomposition and coalescence of NiO particles proceed. In view of the structural rearrangement of powder at the high temperatures 400–700°C, dehydration process is monitored by the decrease of NiO particles surface area at their coalescence. According to the change in the dehydration mechanism, the hierarchically nanostructured material forms, whose particle sizes are in the range 4–5, 9–12, and 18–40 nm.

Structure of lanthanum(III) tris-dipivaloylmethanate

A series of Ln(III) dipivaloylmethanates of the composition Ln(dpm)3 (Ln = La, Tm, Yb) is obtained. It is established that Tm(dpm)3 and Yb(dpm)3 complexes are isostructural with Lu(dpm)3. The crystal structure of [La(dpm)3]2 at 150(2) K is determined (space group P21/n, a = 12.4412(5) Å, b = 28.0579(12) Å, с = 21.9533(8) Å, β = 105.796(2)°, V = 7373.9(5) Å3, Z = 4). The studied compound is isostructural with [Pr(dpm)3]2, [Eu(dpm)3]2, [Gd(dpm)3]2, and [Tb(dpm)3]2 complexes. The crystal structure of the complex is formed by dimeric [La(dpm)3]2 molecules. Thermogravimetric investigations show that the volatility of Ln(dpm)3 increases in the series from [La(dpm)3]2 to Yb(dpm)3. Melting points of the complexes are close to the known literature data.