Synthesis,crystal structure,and properties of [Rh(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl][ReBr<Subscript>6</Subscript>]

A binary complex salt [Rh(NH₃)₅Cl][ReBr₆] has been synthesized and investigated by X-ray diffraction analysis. Crystal data: a = 8.541(5) Å, b = 12.015(6) Å, c = 16.496(9) Å; α = 73.695(10)°, β = 89.746(9)°, γ = 89.676(9)°, V = 1624.7 ų, space group \(P\overline 1 \), Z = 4, D _x = 3.635 g/cm³, R = 0.12. It is shown that the product of thermolysis of the salt in the atmosphere of hydrogen and helium is a solid solution Rh_0.5Re_0.5 with hcp cell parameters a = 2.731(5) Å and c = 4.368(7) Å.     

Thermolysis of [Pt(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>][ReHlg<Subscript>6</Subscript>] (Hlg = Cl,Br). Structure refinement for [Pt(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>][ReCl<Subscript>6</Subscript>]

Thermal decomposition of [Pt(NH₃)₄][ReHlg₆] binary complex salts (Hlg = Cl, Br) in a hydrogen atmosphere has been studied. Polycrystal X-ray diffractometry indicated that two-phase metallic systems are the final products of thermolysis. Structure refinement was performed for [Pt(NH₃)₄][ReCl₆] by the combined technique involving decomposition of the diffractogram into individual reflections, isolation of reflections most sensitive to the position of separate light atoms, and full-profile analysis. Crystal data for PtReN₄Cl₆H₁₂: a = 11.616(1) Å, b = 10.998(1) Å, c = 10.377(1) Å, V = 1148.1 ų, space group Cmca, Z = 4, d _x = 3.831 g/cm³. The indices are R_p = 5.48%, R_wp = 10.01%, R(F²) = 12.62%. The coordination polyhedron of Re is an almost regular octahedron: Re-Cl 2.34–2.36 Å, ∠ Cl-Re-Cl 86.9–90.3°; the coordination polyhedron of Pt is a square: Pt-N 2.04 Å, ∠N-Pt-N 90.4°.     

Synthesis of nonequilibrium Ir<Subscript>x</Subscript>Re<Subscript>1-x</Subscript> solid solutions. Crystal structure of [Ir(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl]<Subscript>2</Subscript>[ReCl<Subscript>6</Subscript>]Cl<Subscript>2</Subscript>

Synthesis of five binary complex salts with an [Ir(NH₃)₅Cl]²⁺ complex cation is described. The counterions are [ReCl₆]^2–, [IrCl₆]^2–, [ReBr₆]^2–, and Cl^–. A polycrystal X-ray diffraction study has been performed for [Ir(NH₃)₅Cl]₂[ReCl₆]Cl₂, and its crystal structure has been determined. A series of Ir _x Re_1–x phases (0.5 x > 1) were obtained by reductive thermolysis. For the Ir-Re system, the history of the V/Z(x) dependence has been refined.Original Russian Text Copyright © 2004 by S. A. Gromilov, S. V. Korenev, I. V. Korolkov, K. V. Yusenko, and I. A. BaidinaTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 508–515, May–June 2004.     

Synthesis and crystal structure of [Cr(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl][PdBr<Subscript>4</Subscript>]

A new binary complex salt — chloropentaamminechromium(III) tetrabromopalladate(II) [Cr(NH₃)₅Cl][PdBr₄] — has been synthesized. The compound was characterized by elemental, X-ray diffraction, and X-ray phase analysis. The salt is isostructural with the previously investigated compounds [M(NH₃)₅Cl][PtCl₄] (M = Ir, Rh, Ru, Co, Cr) and [CM(NH₃)₅Cl][PdBr₄] (M = Ir, Rh, Co). Crystallographic data: space group Pnma, a = 17.068(2) Å, b = 8.315(12) Å, c = 9.653(14) Å; V = 1370.0(3) ų, Z = 4, d _calc = 2.903 g/cm³.     

Crystal structure of [Ir(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl]<Subscript>2</Subscript>[OsCl<Subscript>6</Subscript>]Cl<Subscript>2</Subscript>. Crystal-chemical analysis of the iridium-osmium system

The [Ir(NH₃)₅Cl]₂[OsCl₆]Cl₂ binary complex salt has been prepared, and its structure was investigated by single crystal X-ray diffraction. Crystal data: a = 11.1901(13) Å, b = 7.9138(13) Å, c = 13.4384(18) Å; β = 99.640(3)°, V = 1190.0(2), space group C2/m, Z = 2, FW = 1099.47, d _x = 3.068 g/cm³. Thermolysis products of [Ir(NH₃)₅Cl]₂[OsCl₆]Cl₂, [Ir(NH₃)₅Cl][OsBr₆], (NH₄)₂[OsCl₆]_x[IrCl₆]_1?x , and K₂[OsCl₆]_x[IrCl₆]_1?x were studied by X-ray phase analysis; the unit cell parameters were refined, and the dependence of volume per atom (V/Z) on the composition of the Ir Os_1?x solid solution has been plotted.     

Crystal structure and properties of [M(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>Cl](NO<Subscript>3</Subscript>)<Subscript>2</Subscript>, (M = Ir,Rh, Ru)

The crystal structures of compounds from the series [M(NH₃)₅Cl](NO₃)₂, (M = Ir, Rh, Ru) were described. The compounds crystallized in the tetragonal crystal system, space group I4, Z = 2. Crystal data for [Ir(NH₃)₅Cl](NO₃)₂ (I): a = 7.6061(1) Å, b = 7.6061(1) Å, c = 10.4039(2) Å, V = 601.894(16) ų, ρ_calc = 2.410 g/cm³, R = 0.0087; [Rh(NH₃)₅Cl](NO₃)₂ (II): a = 7.5858(5) Å, b = 7.5858(5) Å, c = 10.41357(7) Å, V = 599.24(7) ų, ρ_calc = 1.926 g/cm³, R = 0.0255; [Ru(NH₃)₅Cl](NO₃)₂ (III): a = 7.5811(6) Å, b = 7.5811(6) Å, c = 10.5352(14) Å, V = 605.49(11) ų, ρ_calc = 1.896 g/cm³, R = 0.0266. The compounds were defined by IR spectroscopy and XRPA and thermal analyses.     

Crystal structure of DienH<Subscript>3</Subscript>[PtCl<Subscript>6</Subscript>]Cl

The DienH₃[PtCl₆]Cl complex was synthesized, and its crystal structure was determined. Crystal data for C₄H₁₆Cl₇N₃Pt: a = 6.8831(3) Å, b = 23.2767(12) Å, c = 9.6058(4) Å, = 90.593(2)°, V = 1538.92(12) ų, space group P2(1)/n, Z = 4, ρ_calc = 2.371 g/cm³.     

Crystal structure of bis(semicarbazido)copper(II) nitrate [Cu(NH<Subscript>2</Subscript>NHC(O)NH<Subscript>2</Subscript>)<Subscript>2</Subscript>](NO<Subscript>3</Subscript>)<Subscript>2</Subscript>

The crystal structure of bis(semicarbazido)copper(II) nitrate [Cu(NH₂NHC(O)NH₂)₂](NO₃)₂ has been studied by X-ray diffraction. Monoclinic crystals, a = 6.835(2) Å, b = 7.733(2) Å, c = 10.320(3) Å, β = 105.701(3)°, V = 525.1(2) ų, space group P2₁/c, Z = 2, d _msd = 2.136 g/cm³, μ(MoK _α) = 2.143 mm⁻¹. The structure was solved with the program for automatic analysis of Patterson’s function and refined by full-matrix least squares in an anisotropic approximation for all non-hydrogen atoms using 753 independent reflections; R ₁ = 0.0203. The square environment of the Cu atom is formed from the amino nitrogen atoms of the hydrazine fragments and the C=O oxygen atoms of the two semicarbazide bidentate molecules (Cu-N 1.928 Å, Cu-O 1.999 Å). The axial positions are occupied by the O atoms of the NO ₃ ⁻ outer-spheric anions (Cu-O 2.505 Å). In the structure, the complex cations and the NO ₃ ⁻ anions are linked into a framework by N-H...O type hydrogen bonds. Original Russian Text Copyright ? 2007 by G. V. Romanenko, Z. A. Savelieva, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No. 2, pp. 370–373, March–April, 2007.     

Study of the Re<Subscript>0.50</Subscript>Rh<Subscript>0.50</Subscript> products of thermobaric treatment

The products of thermobaric treatment of the metastable Re_0.50Rh_0.50 nanocrystalline phase (a= 2.733(2) Å, c = 4.364(4) Å, space group P6₃/mmc, CSR ～5 nm) in a high-pressure chamber were studied. Storage of the phase at 2000°C and 1.5 GPa for 3 min led to the formation of a fused particle (Ø～1 mm). The initial composition did not change, but the coherent scattering region (CSR) increased to 52 nm. An increase to 4 GPa in pressure also did not lead to a decomposition of the metastable Re_0.50Rh_0.50 phase, the unit cell parameters remained the same, and the size of the CSR increased by a factor of four.     

[Co(NH<Subscript>3</Subscript>)<Subscript>6</Subscript>](WO<Subscript>4</Subscript>)Cl: Synthesis,crystal structure,and thermal properties

The crystal structure of [Co(NH₃)₆](WO₄)Cl complex salt is determined by single crystal X-ray. The thermal properties are examined, and the products obtained on heating the salt in different gaseous atmospheres are analyzed by powder X-ray diffraction.     

Synthesis, structure, and properties of [RuNO(NH3)4OH][PtCl4] and [RuNO(NH3)4OH][PdCl4]

Double complex [RuNO(NH₃)₄OH][PtCl₄] (I) and [RuNO(NH₃)₄OH][PdCl₄] (II) salts have been prepared and explored with TGA, IR spectroscopy, powder and single crystals X-ray diffraction. Crystal phases of I and II are isostructural (space group Cmc2₁) and have the following crystal chemical characteristics: a = 8.106 Å, b = 18.190(3) Å, c = 8.097 Å, V = 1194.0 ų, Z = 4, ρ_calc = 3.077 g/cm³ (I), and a = 8.116 Å, b = 18.135 Å, c = 8.062 Å, V = 1186.5 ų, Z = 4, ρ_calc = 2.600 g/cm³ (II). The product of thermal decomposition of I in inert and hydrogen atmospheres is a substitution solid solution Pt_0.5Ru_0.5 with the parameter of the FCC unit cell a = 3.856(3) Å. Thermolysis of II affords two-phase mixtures of limited solid solutions of the metals featuring Ru-based HCP and Pd-based FCC cells. __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 48, No.1, pp.114–121, January–February, 2007.     

Phase transformations of the Re<Subscript>0.3</Subscript>Ir<Subscript>0.7</Subscript> solid solution

Transformations of the nonequilibrium solid solution Re_0.3Ir_0.7 at increased pressure (1–10 GPa) and temperature (2000°C) have been studied. A phase transition from the hexagonal close-packed cell to the face-centered cubic cell without a loss of density and volume per atom has been detected.     

Crystal structure of Ba(VUO<Subscript>6</Subscript>)<Subscript>2</Subscript>

The crystal structure of Ba(VUO₆)₂ was determined by X-ray diffraction at 243 K: monoclinic crystal system, space group P2₁/c, unit cell parameters a=6.4992(6) Å, b=8.3803(8) Å, c=10.4235(9) Å, =104.749(2) °, Z=2. The structure contains close-packed [VUO₆] ₂ ^- layers formed by the dimers of the flattened U₂O₁₂ pentagonal bipyramids and by the dimers of V₂O₈ square pyramids. The neighboring layers are bound by the statistically distributed barium atoms.Original Russian Text Copyright © 2004 by E. V. Alekseev, E. V. Suleimanov, E. V. Chuprunov, and G. K. FukinTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 3, pp. 544–548, May–June 2004.     

Synthesis,structure, and properties of the [RuNO(NH<Subscript>3</Subscript>)<Subscript>5</Subscript>][Co(CN)<Subscript>6</Subscript>] complex containing a photochromic cation

The salt of cobalt hexacyanide with the photochromic mononitrosyl cation [RuNO(NH₃)₅]³⁺ with the composition [RuNO(NH₃)₅][Co(CN)₆] was synthesized. Single crystals of the salt were grown, and the crystal structure was solved. The photochromic properties were studied by differential scanning calorimetry (DSC). Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 545–548, March, 2008.     

High-temperature X-ray diffraction study of thermolysis of the double complex salt [Rh(NH3)5Cl][PtCl4]

The formation process of a nanosize powder of the equilibrium solid solution Pt_0.50Rh_0.50 by thermolysis of the double complex salt [Rh(NH₃)₅Cl][PtCl₄] under hydrogen or helium and in vacuo was studied in situ by X-ray diffraction and synchrotron radiation. The reduction temperature of the metals in the cationic and anionic moieties of the starting complex is the main factor responsible for the mechanism of solid solution formation. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1069–1073, July, 2006.     

Synthesis,structure and thermal decomposition of [Ni(NH<Subscript>3</Subscript>)<Subscript>6</Subscript>][VO(O<Subscript>2</Subscript>)<Subscript>2</Subscript>(NH<Subscript>3</Subscript>)]<Subscript>2</Subscript>

The compound [Ni(NH₃)₆][VO(O₂)₂(NH₃)]₂ was prepared and characterized by elemental analysis and vibrational spectra. The single crystal X-ray study revealed that the structure consists of [Ni(NH₃)₆]²⁺ and [VO(O₂)₂(NH₃)]⁻ ions. As a result of weak interionic interactions V′···O_p (O_p-peroxo oxygen), ([VO(O₂)₂(NH₃)]⁻)₂ dimers are formed in the solid-state. The thermal decomposition of [Ni(NH₃)₆][VO(O₂)₂(NH₃)]₂ is a multi-step process with overlapped individual steps; no defined intermediates were obtained. The final solid products of thermal decomposition up to 600°C were Ni₂V₂O₇ and V₂O₅.     

Synthesis of [M(NH3)5Cl](ReO4)2 (M = Cr, Co, Ru, Rh, Ir) and investigation of thermolysis products. Crystal structure of [Rh(NH3)5Cl](ReO4)2

Complex salts [M(NH₃)₅Cl](ReO₄)₂, where M = Cr, Co, Ru, Rh, Ir, have been prepared. The crystal structure of [Rh(NH₃)₅Cl](ReO₄)₂ was determined by single crystal X-ray diffraction. Crystal data: a = 17.369(4) Å, b = 7.7990(16) Å, c = 11.218(2) Å, V = 1430.5(5) ų, space group C2/m, Z = 4, d _calc = 3.19 g/cm³, R = 0.0447. Complex salts from the above series are shown to be isostructural; they were defined by X-ray crystallography. Thermal decomposition of the compounds in an inert atmosphere and under hydrogen has been studied. According to X-ray phase analysis (XRPA) data, the M_0.33Re_0.67 (M = Co, Ru, Rh, Ir) monophase solid solutions are the products of reduction of the salts under hydrogen.     

[Zn(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>][PtCl<Subscript>6</Subscript>] and [Cd(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>][PtCl<Subscript>6</Subscript>] as precursors for intermetallic compounds PtZn and PtCd

Double complex salts (tetraamminezinc and tetraamminecadmium hexachloroplatinates) have been synthesized. Their thermal properties have been studied, as well as the products of their degradation in hydrogen and helium atmospheres. Optimal thermolysis schedules have been determined. Thermolysis under hydrogen yields intermetallic compounds PtZn and PtCd.     

Synthesis of non-equilibrium PtxOs1−x Solid solutions. Crystal structure of [Pt(NH3)4][OsCl6]

Several non-equilibrium solid solutions belonging to the platinum-osmium systems Os_0.9Pt_0.1, Os_0.8Pt_0.2, Os_0.5Pt_0.5, Os_0.7Pt_0.3, Os_0.75Pt_0.25 are prepared and studied. The thermal decomposition of [Pt(NH₃)₄][OsCl₆] in the hydrogen and helium atmosphere is investigated. It is found that the Pt_0.5Os_0.5 solid solution develops through the formation of (NH₄)₂[OsCl₆] and a metallic phase based on Pt. The crystal structure of a double complex salt [Pt(NH₃)₄][OsCl₆] is studied (X8-APEX Bruker, 1508 independent reflections, R = 2.04%). Crystal data for PtOsN₄Cl₆H₁₂ are: a = 11.6216(5) Å, b = 11.0016(5) Å, c = 10.3819(5) Å, V = 1327.4(1) ų, space group Cmca, Z = 4, d _x = 3.333 g/cm₃. The coordination polyhedron around Os is octahedral: 〈Os-Cl〉 2.357 Å, ∠Cl-Os-Cl 89.5–90.5°, while around Pt it is square-planar: Pt-N 2.046 Å, ∠ N-Pt-N 89.59° and 90.41°.     

XAFS investigation of [Pd(NH<Subscript>3</Subscript>)<Subscript>4</Subscript>][AuCl<Subscript>4</Subscript>]<Subscript>2</Subscript> and its thermolysis products

Thermolysis of double complex salt [Pd(NH₃)₄][AuCl₄]₂ has been studied in helium atmosphere from ambient to 350 °C. The XAFS of Pd K and Au L₃ edges and thermogravimetry measurements have been carried out to characterize the intermediates and the final product. In the temperature range 115–160 °C the complex is decomposed to form Pd(NH₃)₂Cl₂ and AuCl_4−x N _x species with x ranging from 2 to 3. Subsequent heating of the intermediate up to 300 °C leads to the total loss of NH₃. The Au–Cl and Au–Au bonds form the local environment of Au at the stage of decomposition while only four chlorine atoms are around Pd. At the temperature of 330 °C the Au and Pd nanoparticles as well as residues of palladium chloride are detected. The final product consists of separated Au and Pd nanoparticles.