N. I. Alferova

Preparation of metal-polymer composites through the thermolysis of Fe(II), Co(II), and Ni(II) maleates

Metal-polymer composites have been prepared through the thermolysis of the [M1(H2O)2(C4H2O4)] · H2O (M1 = Co(II), Ni(II)) neutral maleates and [M2(H2O)4(C4H3O4)2] (M2 = Fe(II), Co(II), Ni(II)) acid maleates. In the polymer matrix of the Fe-containing composite, we identified metal, Fe2O3, and Fe3O4 particles, with slight densification of the matrix around them. The polymer matrix of the cobalt maleate-derived composite contained four types of nanoparticles: α-Co, β-Co, and CoO in polymer shells and Co3O4 with no polymer shell. The decomposition of the nickel maleates yielded homogeneous nickel nanoparticles (4–5 nm) covered with two to five graphene layers. The Co-containing composite was found to be a dielectric. The Ni-containing composite exhibited variable range hopping conduction in the range T ≤ 50 K.

LAYERED COMPOUNDS BASED ON PERFORATED GRAPHENE

A method to obtain previously unknown layered structure composed of stacks of perforated graphene sheets is developed. The method consists in the thermal decomposition of graphite oxide in the concentrated H2SO4 and H3PO4 medium. In order to confirm the presence of holes in graphene layers, a large set of chemical and physicochemical analysis methods are applied. Based on a new matrix, treated thermally and chemically, layered compounds are obtained: oxide, fluoride, and fluoroxide of two types. The obtained compounds are analyzed by transmission electron microscopy, infrared absorption spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, thermogravimetric analysis, and powder X-ray diffraction.

Properties of BCxNy films grown by plasma-enhanced chemical vapor deposition from N-trimethylborazine-nitrogen mixtures

Boron carbonitride films of various compositions have been grown by plasma-enhanced chemical vapor deposition using N-trimethylborazine as a single-source precursor and nitrogen as a plasma gas and an additional nitrogen source. Experiments were performed at various deposition temperatures and rf powers. The films were characterized by ellipsometry, atomic force microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, IR and Raman spectroscopies, synchrotron X-ray diffraction, energy dispersive X-ray microanalysis, and spectrophotometry. The results demonstrate that, under the conditions of this study, the growth kinetics and physicochemical properties of boron carbonitride layers are influenced by both the substrate temperature and rf power. Conditions are found for producing boron carbonitride films transparent in the UV through visible spectral region.

Binuclear cluster complexes of molybdenum containing 2,2′-bipyridine and 1,10-phenanthroline: Synthesis and structure

By the interaction between (Et4N)2[Mo2O2S8] and I2 in DMF with a subsequent addition of 2,2′-bipyridine or 1,10-phenanthroline, new binuclear complexes [Mo2O2S2I2(bipy)2] (1) and [Mo2O2S2I2(phen)2] (2) are obtained. The structure of [Mo2O2S2I2(bipy)2] is determined using single crystal X-ray diffraction. The compounds are characterized by elemental analysis and IR spectra. The [MoO(S2)2(bipy)] complex as a product of oxidative destruction of 1 is isolated and characterized.

Nitrosoruthenium hydroxo and aqua complexes of the trans-dipyridine series: Synthesis, structures, and characterization

A procedure for the synthesis of trans-Ru(NO)(Py)2Cl2(OH) (I) from K2[Ru(NO)Cl5] was proposed. Treatment of hydroxo complex I with HCl or H2SO4 at room temperature gave the corresponding salts trans-[Ru(NO)(Py)2Cl2(H2O)]Cl · 2H2O (II) and trans-[Ru(NO)(Py)2Cl2(H2O)]HSO4 (III). All the complexes obtained were characterized by 1H and 13C NMR and IR spectroscopy and elemental analysis; their structures were determined by X-ray diffraction. The structures are stabilized by π-stacking between the pyridine ligands of adjacent complex species.

Synthesis and spectroscopic properties of (C2FxBr0.01 · yCH3CN)n (0.5 < x < 1.0) intercalation compounds

Abstract(C2FxBr0.01 · yCH3CN)n intercalation compounds, with (C2FxBr0.01)n (0.5 < x < 1.0) as a host and CH3CN as a guest (x and y are stoichiometric coefficients), have been synthesized. The influence of fluorine content on the spectroscopic characteristics of the intercalation compounds with acetonitrile has been studied by Raman, IR, and X-ray photoelectron spectroscopies. The macroscopic properties of the intercalation compounds are shown to correlate with their spectroscopic characteristics. The data for the compounds stored in air for about a year indicate that their surface and interior differ in structure.

Thermolysis of copper(II) salts of maleic acid. Synthesis of metal-polymer composites

The thermal decomposition of neutral ([Cu(H2O)(C4H2O4)]) and acidic ([Cu(H2O)4](C4H3O4)2) maleates can conventionally be divided into four stages: (1) dehydration, (2) polymerization, (3) isomerization of the maleate ion to the trans form with the simultaneous reduction Cu(II) → Cu(I), and (4) decarboxylation of copper(I) fumarate. The third and fourth stages of the decomposition of these salts coincide. The residue after the thermolysis of copper(II) maleates in a He flow is a composite consisting of aggregates from 50 nm to several microns in size. Spherical conglomerates (50–200 nm) containing many spherical Cu particles (5–10 nm) are incorporated into the organic polymer matrix of these aggregates.

Crystal structures of rhodium(III) aqua ion with tetrahedral anions

The crystal structures of compounds of the composition [Rh(H2O)6]2(SO4)3·5H2O (I) and [Rh(H2O)6]PO4 (II) are determined. Crystallographic data for I: a = 7.272(9) Å, b = 27.047(1) Å, c = 12.464(9) Å, β = 97.038(10)°, P21 space group, Z = 4, dx = 2.184 g/cm3; for II: a = 9.746(6)Å, b = 6.877(7) Å, c = 23.623(6) Å, β = 100.601(10)°, C2/c space group, Z = 8, dx = 2.611 g/cm3. Compounds are analyzed by IR spectroscopy and powder XRD. Crystalline phase I is well soluble in water, whereas II is almost insoluble.

Crystal structure of adducts of copper(II) acetylacetonate and hexafluoroacetylacetonate with 4-aminopyridine

Single crystal X-ray diffraction is used to investigate two synthesized β-diketonate complexes of copper(II) with aminopyridine: Cu(4-NH2Py)(aa)2 (I) and Cu(4-NH2Py)(hfa)2 (II). The crystals of I and II have a monoclinic system; the unit cell parameters of I are: P21/n space group, a = 8.2921(3) Å, b = 14.7243(5) Å, c = 13.4970(4) Å, β = 102.426(1)°, V = 1609.32(9) Å3, Z = 4; for II: C2/c space group, a = 23.5704(5) Å, b = 11.4977(2) Å, c = 16.0285(3) Å, β = 109.265(1)°, V = 4100.6(1) Å3, Z = 8. The structures of I and II are molecular; they are composed of isolated molecules. The coordination polyhedron of the copper atom is formed by the O atoms of two acetylacetonate ligands (Cu-O 1.940(2)–2.171(2) I and the O atoms of two hexafluoroacetylacetonate ligands (Cu-O 1.940(2)–2.215(3) Å) in II. The molecules of 4-NH2Py are bonded to the copper atom via the nitrogen atom of the aromatic ring (Cu-N 2.008(2) Å in I and Cu-N 1.978(3) Å in II). Noncoordinated amino groups join the molecules of the complexes together by means of N-H…O hydrogen bonds.

Thermolysis characteristics of salts of o-phthalic acid with the formation of Fe, Co, Ni, Cu metal particles

Studies of the thermolysis of ortho-[Ni(H2O)2(C8H4O4)](H2O)2, [Cu(H2O)(C8H4O4)], and acid [M(H2O)6](C8H5O4)2 (M(II) = Fe(II), Co(II), and Ni(II)), [Cu(H2O)2(C8H5O4)2] phthalates reveal that the solid products of their decomposition are composites with nanoparticles embedded in carbon–polymer matrices. Metallic nanoparticles with oxide nanoparticle impurities are detected in iron/cobalt polymer composites, while nickel/copper composites are composed of only metallic particles. It is found that nickel nanoparticles with the diameters of 6–8 nm are covered with disordered graphene layers, while the copperbased composite matrix contains spherical conglomerates (50–200 nm) with numerous spherical Cu particles (5–10 nm).