C(methyl)–H ⋅ ⋅ ⋅ π(aryl) Interaction Stabilizing Molecular Conformation. X-Ray Crystal Structure of an Inclusion Compound of a Nonprotic Host with Nitromethane Guest

In the cocrystal formation of a nonprotic polar (host) molecule (1) with nitromethane (guest) several weak, but directional, intermolecular interactions have vital importance. The endo conformation of the (N)-xylene group of the polycyclic succinimide-based host 1 is stabilized by a C_methyl $---$ H ??? π interaction [C ??? π /H ??? π distances are 3.554(7)/2.57 Å, the C $---$ H ??? π angle is 159^○], and the crystal packing is governed by dipole–dipole type interhost (C $ =$ )O ??? C( $ =$ O) connection [C ??? O $ =$ 3.000(5) Å and <C $ =$ O ??? C $ =$ 159.8(3)^○] in conjunction with possible C $---$ H ??? O interactions [with C ??? O distances ranging between 3.20 and 3.50 Å] involving the polar groups of both host and guest. Crystal data: 1 ??? nitromethane (1:1), C₂₆H₂₁O₂ N ? CH₃NO₂, M _w = 440.50, P2 ₁/n, a = 14.143(1), b = 7.973(1), c = 20.291(2) Å, β = 95.183(9)^○, Z = 4, D _c = 1.2840(2) g cm^?3, R = 0.055 for 1709 reflections.     

Copper complexes with N-allylisoquinolinium halides: Synthesis and crystal structures of [C9H7N(C3H5)]2CuIICl2.86Br1.14, [C9H7N(C3H5)CuIBr2] · H2O, and [C9H7N(C3H5)CuIBr2]

Crystals of the copper bromide complexes with N-allylisoquinolinium halides of the composition [C₉H₇N(C₃H₅)]₂Cu^IICl_2.86Br_1.14 (I), [C₉H₇N(C₃H₅)]Cu^IBr₂ · H₂O (II), and [C₉H₇N(C₃H₅)]Cu^IBr₂ (III) are prepared by ac electrochemical synthesis, and their structures are studied by X-ray diffraction analysis (DARCh-1 (for I) and KUMA/CCD (for II and III) diffractometers). The crystals of compound I are monoclinic: space group P2₁/n, a = 15.053(5) Å, b = 10.486(4) Å, c = 17.179(10) Å, γ = 109.77(3)°, V = 2552(4) ų, Z = 4. The crystals of complex II are triclinic: space group P $\overline 1 $ , a = 7.040(1) Å, b = 7.610(2) Å, c = 12.460(2) Å, α = 79.54(3)°, β = 86.73(3)°, γ = 89.51(1)°, V = 655.4(2) ų, Z = 2. The crystals of complex III are monoclinic: space group P2₁/n, a = 12.799(1) Å, b = 7.692(1) Å, c = 13.491(1) Å, β = 111.08(1)°, V = 1239.3(2) ų, Z = 4. The structure of compound I is built of the Cu^IIX ₄ ^2? tetrahedra and N-allylisoquinolinium cations united by the C-H···X contacts into corrugated layers. The crystal structure of π-complex II is formed of dimers of the composition [C₉H₇(C₃H₅)]₂ Cu ₂ ^I Br₄ forming layers in the direction of the z axis due to the C-H···X contacts. An important role in structure formation belongs to water molecules that cross-link the organometallic layers through the O-H···X contacts into a three-dimensional framework. When kept in the mother liquor for 6 months, the crystals of compound II transformed into crystals of compound III, whose structure consists of {[C₉H₇(C₃H₅)]₂Cu ₂ ^I Br₄} _n columns united through the C-H···Br contacts (H···Br 2.84(3)?2.92(4) Å) into a three-dimensional framework.     

2-(diphenylphosphinylmethoxy)aniline: Synthesis,vibrational spectra,and crystal structure

The synthesis, vibrational spectra, and X-ray diffraction analysis results for 2-(diphenylphosphinylmethoxy) aniline, 2-[(C₆H₅)₂P(O)OCH₂]C₆H₄NH₂(I), are described. The crystals are monoclinic: a = 18.4515(17) Å, b = 10.5421(12) Å, c = 17.897(2) Å, β = 104.479(8)°, V = 3370.7(6) ų, Z = 8, space group P2₁/c, R = 0.0546 for 1770 reflections with I > 2σ(I). The unit cell contains two crystallographically independent molecules Ia and Ib joined by an N-H …O hydrogen bond between a hydrogen atom of the amino group of aniline in molecule Ia (Ib) and the phosphoryl oxygen atom of molecule Ib (Ia) (O…H 2.18 and 2.19 Å, N…O, 2.979(5) and 3.000(5) Å; NHO angle, 154° and 157°).     

Study of new molecular and crystal structures of 4,4,10,10-tetramethyl-1,3,7,9-tetraazospiro[5.5]undecane-2,8-dione and its salts: Monochloride,mononitrate, and tetraiodotellurate

This is the first work to synthesize 4,4,10,10-tetramethyl-1,3,7,9-tetraazospiro[5.5]undecane-2,8-dione monohydrate, monochloride, mononitrate, and teteraiodotellurate: C₁₁H₂₀N₄O₂·H₂O (I), C₁₁H₂₁N₄O ₂ ⁺ ·Cl^? (II), C₁₁H₂₁N₄O ₂ ⁺ ·NO ₃ ^? (III), and 2(C₁₁H₂₁N₄O ₂ ⁺ )·TeI ₄ ^2? ·C₃H₆O (IV) and determine their structures. Crystals of I are monoclinic: space group P2₁/c, at 298 K a = 5.7118(7) Å, b = 17.842(2) Å, and c = 13.5905(16) Å; β = 91.621(11)°; V = 1384.5(3) ų; d _x = 1.239 g/cm³, Z = 4. Crystals of II are tetragonal: space group P4₃, at 298 K a = 6.4134(3) Å and c = 34.292(2) Å; V = 1410.47(14) ų; d _x = 1.303 g/cm³; Z = 4. Crystals of III are triclinic: space group \(P\bar 1\) , at 298 K a = 8.7614(14) Å, b = 9.3904(18) Å, and c = 10.028(2) Å; α = 63.27(2)°, β = 78.591(16)°, and γ = 84.308(15)°; V = 722.3(2) ų; d _x = 1.40 g/cm³; Z = 2. Crystals of IV are triclinic: space group \(P\bar 1\) , at 100 K a = 10.4630(4) Å, b = 11.9372(6) Å, and c = 16.4118(5) Å; α = 72.058(3)°, β = 76.406(3)°, and γ = 87.029(3)°; V = 1895.04(12) ų; d _x = 2.06 g/cm³; Z = 2. The synthesis of s and p metals with spirocarbone in acetone medium is found to be impossible due to the protonation by the oxygen atom of the carbonyl group. The main crystalline product of the complexation reaction is a monosalt. Evidence is provided that the recrystallization and drying of the synthesized spirocarbone preparation yields monohydrate (I); its purity and monophasity is confirmed by a Rietveld refinement of the powder X-ray pattern. The lattice parameters at room temperature are: a = 5.6885(12) Å, b = 17.8496(12) Å, and c = 13.518(3) Å; β = 91.449(15)°; V = 1372.1(4) ų. The sample is monophasic.     

π-Complexes of copper(I) halides with 3-(allylamino)-(C3H5NHC2H4CN, Apn) and 3-(diallylamino)-((C3H5)2NC2H4CN, Dapn)-propanenitrile. syntheses and crystal structures of compounds [CuCl(Apn)], [(H+Apn)Cu2Cl3], [(H+Dapn)CuCl2], and [(H+Dapn)CuBr2]

The ??-complexes [CuCl(C₃H₅NHC₂H₄CN)] (I), [(C₃H₅NH₂C₂H₄CN)Cu₂Cl₃] (II), [((C₃H₅)₂NHC₂H₄CN)CuCl₂] (III), and [((C₃H₅)₂NHC₂H₄CN)CuBr₂] (IV) are obtained as single crystals by the ac electrochemical synthesis on copper wire electrodes from ethanolic solutions of 3-(allylamino)propanenitrile, 3-(diallylamino)propanenitrile, and CuX₂ (X = Cl, Br). Their crystal structures are determined. The crystals of compounds I, III, and IV are monoclinic, space group P2₁/c, Z = 4. The crystals of compound II are triclinic, space group P $\bar 1$ , Z = 2. The unit cell parameters are a = 11.125(4), b = 8.769(4), c = 8.570(4) ?, ?? = 90.94(4)°, V = 835.9(6) ?³ (I); a = 6.2566(4), b = 7.5975(6), c = 11.1251(8) ?, ?? = 90.896(6)°, ?? = 92.827(5)°, ?? = 94.340(5)°, V = 526.57(7) ?³ (II); a = 11.656(4), b = 6.992(4), c = 14.681(5) ?, ?? = 100.89(4)°, V = 1174.9(9) ?³ (III); a =11.845(4), b = 7.282(4), c=14.855(5) ?, ?? = 100.37(4)°, V = 1260.4(9) ?³ (IV). The coordination mode of the Cu(I) atom in complex I includes two halogen atoms, the C=C bond, and the secondary amine N atom. The coordination environment in isostructural crystals of complexes III and IV is formed by the C=C bond and three halogen atoms as in complex II.     

Synthesis, crystal structures, and luminescence spectra of the coordination compounds of cadmium(II) iodide with hexamethylenetetramine

Coordination compounds [Cd_1.5I₃(HMTA) · H₂O] (I) and [CdI₂(HMTA) · H₂O] (II) are synthesized by the reaction of CdI₂ with hexamethylenetetramine (HMTA, C₆H₁₂N₄) with the 1: 1 ratio in ethanol, and their structures are determined. The crystals of compound I are triclinic, space group P $ \bar 1 $ , a = 8.027(1), b = 9.391(1), c = 10.382(1)?, ?? = 66.64(1)°, ?? = 86.18(1)°, ?? = 73.63(1)°, V = 749.2(1) ?³, ??_calcd = 3.136 g/cm³, Z = 2. The crystals of compound II are triclinic, space group P $ \bar 1 $ , a =7.713(1), b = 8.192(1), c = 12.101(1)?, ?? = 80.32(1)°, ?? = 89.57(1)°, ?? = 7.30(1)°, V = 725.0(1) ?³, ??_calcd = 2.402 g/cm³, Z = 2. Structure I includes two types of cadmium complexes. The Cd(1) atom is coordinated through the octahedral mode by three pairs of the I, N(HMTA), and O(H₂O) atoms. The coordination polyhedron of the Cd(2) atom is a distorted tetrahedron (three I atoms and one N atom). The structure contains infinite strips consisting of tetranuclear cyclic fragments joined by the Cd(1) atoms due to the bridging iodine and nitrogen atoms. In structure II, the Cd atom is coordinated through the tetrahedral mode by two iodide ions and the N(HMTA) and O(H₂O) atoms. The interaction between the complexes occurs due to hydrogen bonds O-H??N to form supramolecular chains along the direction [010]. In each HMTA molecule, one of four nitrogen atoms is a proton acceptor in the hydrogen bonds, one nitrogen atom is coordinated, and two N atoms are terminal. Compound II in the solid state has photoluminescence with maxima at 443, 470, and 518 nm.     

Synthesis, crystal structure, and IR spectral study of Na[(UO2)(C3H7COO)3] · 0.25H2O and K[(UO2)(C3H7COO)3]

Synthesis, IR spectral study and X-ray diffraction analysis of single crystals of Na[(UO₂)(C₃H₇COO)₃] · 0.25H₂O (I) and K[(UO₂)(C₃H₇COO)₃] (II) were carried out. Compound I is monoclinic, unit cell parameters are: a = 13.5671(15) ?, b = 20.070(2) ?, c = 13.6139(15) ?, ?? = 106.839(2)°, space group P2₁, Z = 8, R = 0.0493. Compound II is orthorhombic, unit cell parameters are: a = 17.1325(9) ?, b = 19.6966(11) ?, c = 21.9686(11) ?, space group P2₁2₁2₁, Z = 16, R = 0.0563. Mononuclear groups [UO₂(C₃H₇COO)₃]^? related to the A ₃ ⁰¹ crystal-chemical group (A = UO ₂ ²⁺ , B ⁰¹ = C₃H₇COO^?) of uranyl complexes are the uranium-containing structural units of crystals I and II. The data of IR spectral study agree well with X-ray diffraction data.     

Isomorphous crystal structures of 4,7,13,16,21,24-hexaoxo-1,10-diaziniabicyclo[8.8.8]·hexacosane bis(tribromide) and bis(bromoiodide)

Two compounds, 7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(tribromide) and bis(bromodiiodide) — [H₂(Crypt-222)]²⁺·2Br ₃ ^? (I) and [H₂(Crypt-222)]²⁺·1.45(BrI₂)^?·0.4(Br₂I)^?·0.15 I ₃ ^? (II) — are prepared and characterized by single crystal XRD; the refinement of the second compound was more accurate. Isomorphous monoclinic structures (I, space group C2/c, Z = 4, a = 12.090, b = 15.833 Å, c = 15.732 Å, β = 95.83°; II, a = 12.548 Å, b = 16.417 Å, c = 15.748 Å, β = 94.53°) are solved by a direct method and refined in the anisotropic full-matrix approximation to R = 0.057 (I) and 0.044 (II) using all 2635 (I) and 2852 (II) measured independent reflections (automated CAD-4 diffractometer, λMoK _α). In the structures of I and II one of the trihalide anions sits at the inversion center i(000), and the second trihalide anion and the dication [H₂(Crypt-222)]²⁺ are situated at crystallographic axis 2. In the structure of II iodine is located in the center of trihalide anions, while the terminal atoms are disordered and are represented by a statistical combination of iodine and bromine atoms.     

Cesium tetrakis(1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluorobutane-1,3-diono)europiate(III): Synthesis, crystal structure, and luminescence properties

Anionic complex Cs⁺[EuL₄]^? (I) is synthesized by the reaction of Eu(NO₃)₃ · 6H₂O with 1-(1,5-dimethyl-1H-pyrazol-4-yl)-4,4,4-trifluorobutane-1,3-dione (HL) and CsOH in an aqueous-alcohol medium. Unstable adduct Cs⁺[EuL₄]^? · 2CH₂Cl₂ (Ia) is obtained from a solution in CH₂Cl₂. The structure of complex Ia is determined by X-ray diffraction analysis. The crystals of complex Ia at 100 K are monoclinic, a = 10.8435(5), b = 20.1353(9), c = 23.355(1) Å, β = 92.548(1)°, V = 5094.3(4) ų, space group P2₁/n, Z = 4, and R = 0.0294. The coordination number of the Cs⁺ ion is 9. The Cs⁺ ion forms shortened (up to 3.3 Å) contacts with the O, N, and F atoms of four diketonate fragments joining the molecules into a three-dimensional structure.     

Extractive and sorption preconcentration of rhenium(VII) ions with the use of bis(diphenylphosphoryl)-substituted aza podand

Interfacial distribution of trace amounts of ReO ₄ ^? ions between aqueous solutions of mineral acids and solutions of diphosphoryl-substituted aza podand [Ph₂P(O)CH₂CH₂OCH₂CH₂]₂NBu (I) in dichloroethane was studied. The stoichiometry of extracted complexes was determined, the influence of HClO₄, HNO₃, HCl, and H₂SO₄ concentration in aqueous phase and the nature of organic solvent on the efficiency of transition of ReO ₄ ^? ions into organic phase was considered. Aza podand I shows larger extraction ability toward Re(VII) than monophosphorylated amines. The possibility of selective extraction and preconcentration of ReO ₄ ^? ions by a complex-forming sorbent obtained by the noncovalent binding of compound I on the surface of carbon nanotubes was shown.     

Heat capacity and thermodynamic functions of manganite ferrites NdMIMnFeO5 (MI = Li, Na) in the range of 298–673 K

The heat capacities of the new manganite ferrites NdM^IMnFeO₅ (M^I = Li, Na) are investigated in the range of 298.15–673 K by dynamic calorimetry. It is found that in the investigated temperature range, C _p ^○ ～ f(T) curves exhibit λ-shaped effects at 348 and 473 K for NdLiMnFeO₅, and at 423 K for NdNaMnFeO₅, corresponding probably to phase transitions of the second kind. Equations describing the experimentally obtained C _p ^○ ～ f(T) curves are derived, and the temperature dependences of the investigated compounds’ thermodynamic functions, S○(T), H○(T) ? H○(298.15), and Φ ^xx (T), are calculated.     

Synthesis and crystal structure of the complex N,N-dimethylanilinium dicitratoborate monohydrate

N,N-Dimethylanilinium dicitratoborate monohydrate [C₆H₅NH(CH₃)₂][(C₆H₆O₇)₂B]·H₂O (I) was synthesized for the first time. Single crystals were obtained in an aqueous solution; the crystal structure was studied by X-ray crystallography. Crystals of I are triclinic, space group $P\bar 1$ , a = 9.7017(2) ?, b = 11.0475(2) ?, c = 12.6282(2) ?, ?? = 106.595(2)°, ?? = 106.931(1)°, ?? = 103.568(1)°, V = 1163.97(4) ?³, Z = 2, ??_calc = 1.516 g/cm³. The structural units of compound 1 are large complex dicitratoborate anions with a spiran structure, N,N-dimethylanilinium cations, and crystal water molecules. The crystal packing is a three-dimensional framework. A hydrogen-bond system is formed by seven independent contacts O(N)-H??O.     

Coordination behavior of 1,4-diallylpiperazinium and 1-allyloxybenzotriazole toward silver(I) in the crystalline π-complexes [Ag2(C4H8N2(C3H5)2(H+)2)(H2O)2(NO3)2](NO3)2 and [Ag(C6H4N3(OC3H5)(NO3))]

Reactions of a solution of AgNO₃ in aqueous methanol with solutions of 1,4-diallylpiperazine (acidified with HNO₃ to pH = 4) and 1-allyloxybenzotriazole in ethanol gave the crystalline silver(I) π-complexes [Ag₂(C₄H₈N₂(C₃H₅)₂(H⁺)₂)(H₂O)₂(NO₃)₂](NO₃)₂ (I) and [Ag(C₆H₄N₃(OC₃H₅)(NO₃))] (II). Their crystal structures were determined by X-ray diffraction. Crystals of complexes I and II are monoclinic, space group P2₁/c; for I: a = 7.053(3)Å, b = 9.389(3)Å, c = 15.488(4)Å, β = 91.60°, V = 1025.3(6)ų, Z = 4; for II: a = 10.650(4)Å, b = 15.062(5)Å, c = 7.412(4)Å, β = 104.20(3)°, V = 1152.6(8)ų, Z = 4. In both structures, the organic components act as bidentate ligands forming with AgNO₃ 34- and 14-membered topological rings, respectively. In complex I, the nearly tetrahedral environment of the Ag(I) atom is made up of the olefinic C=C bond, the O atoms of the nitrate anions, and the water molecule. 1-Allyloxybenzotriazole in structure II causes the deformation of the coordination polyhedron of Ag into a trigonal pyramid via inclusion of the ligand N atom in its coordination sphere. The topological units of the complexes form infinite polymer layers linked by anionic NO ₃ ^? bridges. In structure I, these layers are united through a system of hydrogen bonds into a three-dimensional framework.     

A Salt-Like Compound Containing the Cation [Tris(1,10-Phenanthroline)manganese(II)](2+) and the Anion 3,3-Commo-Bis[η5-1,2-Dicarba-(3)-Cobalt(III)-closo-Dodecaborate](1–), [MnII(1,10-C12H8N2)3]2+{CoIII[η5-(3)-1,2-B9C2H11]2}– 2: Synthesis and Study

In this paper, the results of a comparative study of a salt-like paramagnetic Mn(II) (d ⁵) complex [Mn^II(1,10-C₁₂H₈N₂)₃]²⁺[Co^III(B₉C₂H₁₁)₂]^– ₂ (I) against [Mn^II(1,10-C₁₂H₈N₂)₂(NCS)₂]⁰ (II) and [Mn^II(1,10-C₁₂H₈N₂)₃]²⁺[B₉C₂H₁₂]^– ₂ (III) are presented. Complexes I and III were synthesized by precipitating the Mn(II) cations with the corresponding anions in the stoichiometric ratio at a pH of ～ 4.5 and were studied by X-ray diffraction analysis on single crystals; by IR, Raman, and EPR spectroscopy; and using magnetochemical methods. The structures and crystal-chemical parameters of I at 190 and 293 K are identical. The crystals are mono-clinic; space group P2₁/n. Two crystallographic types of the [Co(B₉C₂H₁₁)₂]^– anion in structure I have different conformational combinations (cisoid and transoid) of the –C₂– groups in each pair of the B₉C₂H^2– ₁₁ cluster ligands. The short contacts C–H^δ+···^δ–H–B between different-type hydrogen atoms show themselves in the IR spectra. The apparent magnetic moments of the Mn(II) atom in I, II, and III at 293 K correspond to μ = 5.86 μ_B and do not depend on its ligand or anion environment. The temperature dependences μ = f(T) pass through a maximum at about 20 K, which suggests the occurrence of ferromagnetic exchange interactions in complexes I and III, which both contain cluster carborane derivatives with three-dimensional aromaticity.     

Synthesis and structural characterization of binuclear ytterbium(III) complexes with 2-amino and 3-amino benzoic acid

Two novel homobinuclear ytterbium(III) complexes, [Yb₂(2AMB)₆(H₂O)₄] · 2C₂H₆O (I) and Yb₂(3AMB)₆(H₂O)₄] · 3H₂O (II) (2AMB = 2-aminobenzoic acid, 3AMB = 3-aminobenzoic acid) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and X-ray crystallography (CIF files CCDC nos. 950103 (I), 921652 (II)). Complex I crystallizes in triclinic space group \(P\bar 1\) and complex II crystallizes in monoclinic space group P2₁/n. X-ray analysis shows that both complexes (I, II) have the dinuclear structure. The central Yb³⁺ ions in both complexes are eight-coordinated adopting distorted YbO₈ dodecahedral geometry. Each Yb³⁺ ion is coordinated to two O atoms from bridging carboxylate, four O atoms from the chelating carboxylate ligands and two O atoms of water molecules. The crystal structure of I and II are stabilized by N-H…O, O-H…O, O-H…N, and C-H…O hydrogen bonds, C-H…π interactions and weak π-π stacking interactions.     

Synthesis, structure, and activity evaluation of two silver(I) complexes as Helicobacter pylori urease inhibitors

Two silver(I) compounds, [Ag(R,R-hxn)](C₇H₄BrO₂) · 2H₂O (I) (Chxn = 1,2-diaminocyclohexane) and [Ag(C₅H₆N₂)₂]₂(C₈H₄O₄) · 10H₂O (II), were synthesized and complex I was structurally characterized by X-ray crystallography. Compound I contains a catena-(trans-1,2-diaminocyclohexane) silver polycation ([Ag(Chxn)]_∞) in a roughly linear fashion, while II possesses a linear-type silver monocation. Compounds I and II were evaluated for their inhibitory activities against Helicobacter pylori urease in vitro. Both were found to have strong inhibitory activities against H. pylori urease comparable to that of acetohydroxamic acid.     

Synthesis and crystal structure of Cs2[(UO2)2(C2O4)3] and Cs2[UO2(C3H2O4)2] · H2O

Cs₂[(UO₂)₂(C₂O₄)₃] (I) and Cs₂[UO₂(C₃H₂O₄)₂] · H₂O (II) have been synthesized and studied by X-ray diffraction. The crystals of complexes I and II are monoclinic: a = 8.1453(2) Å, b = 8.9831(2) Å, c = 11.3897(4) Å, β = 104.0950(10)°, V = 808.29(4) ų, space group P2₁/n, Z = 2, and R ₁ = 0.0255 for I and a = 9.6998(2) Å, b = 17.8686(3) Å, c = 8.2074(2) Å, β = 97.5780(10)°, V = 1410.10(5) ų, space group P2₁/c, Z = 4, and R ₁ = 0.0287 for II. The uranium-containing structural units of complexes I and II are [(UO₂)₂(C₂O₄)₃]^2? chains and [UO₂(C₃H₂O₄)₂] ₂ ^4? dimers, which belong to the AK _0.5 ⁰² T¹¹ and AT¹¹B⁰¹ crystallochemical groups (A = UO ₂ ²⁺ , K⁰² and T¹¹ = C₂O ₄ ^2? , T¹¹ and B⁰¹ = C₃H₂O ₄ ^2? ) of uranyl complexes.     

Synthesis of bismuth complexes from bismuth iodide and ammonium and phosphonium salts

The complexes [Et₂NH₂] ₃ ⁺ [BiCl₆]^3? (I), [NH₄]⁺[BiI₄(C₅H₅N)₂]^?·2C₅H₅N (II), [Ph₃MeP] ₂ ⁺ [BiI₅]^2? (III), [Ph₃MeP] ₂ ⁺ [BiI₅(C₅H₅N)]^2?·C₅H₅N (IV), [Ph₃MeP] ₃ ⁺ [Bi₃I₁₂]^3? (V), [Ph₃(i-Pr)P] ₃ ⁺ [Bi₃I₁₂]^3?·2Me₂C=O (VI), [Ph₃BuP] ₂ ⁺ [Bi₂I₈·₂Me₂C=O]^2? (VII), and [Ph₃BuP] ₂ ⁺ [Bi₂I₈·2Me₂S=O]^2? (VIII) were obtained by reactions of bismuth iodide with ammonium and phosphonium iodides in acetone, pyridine, or dimethyl sulfoxide.     

Synthesis and crystal structure of [UO2(L)(OH)], (CN3H6)2[(UO2)2CrO4(L)4 · 2H2O and [UO2(H2O)5][(UO2)2Cr2O7(L)4] (where L is picolinate ion)

[[UO₂(L)(OH)] (I), (CN₃H₆)₂[(UO₂)₂CrO₄(L)₄] · 2H₂O (II), and [UO₂(H₂O)₅][(UO₂)₂Cr₂O₇(L)₄] (III) crystals, where L is picolinate ion C₅H₄NCOO^?, have been synthesized and studied by X-ray diffraction and IR spectroscopy. Complex I crystallizes in triclinic system with the unit cell parameters a = 6.2858(5) Å, b = 7.9522(5) Å, c = 8.3598(6) Å, α = 79.527(6)°, β = 87.760(6)°, γ = 79.126(6)°, space group P $\bar 1$ , Z = 2, R = 0.0306, and complexes II and III crystalize in monoclinic system with a = 8.8630(9) Å, b = 13.4540(13) Å, c = 31.266(3) Å, β = 93.118(3)°, space group C2/c, Z = 4, R = 0.0187 (II), and a = 7.3172(4) Å, b = 15.4719(8) Å, c = 16.6534(10) Å, β = 98.943(4)°, space group P2₁/m, Z = 2, R = 0.0588 (III). The structure of complex I is built of electronegative [UO₂(L)(OH)] chains, which belong to the AT¹¹M² crystallochemical group (A = UO ₂ ²⁺ , T¹¹ = L, M² = OH^?) of uranyl complexes. The structure of complexes II and III contains [(UO₂)₂(L′)(L)₄]^2? dimers (L′ = CrO ₄ ^2? or Cr₂O ₇ ^2? ), which belong to the A₂B²B ₄ ⁰¹ group (A = UO ₂ ²⁺ ,B² = L′, B⁰¹ = L). The specifics of intermolecular interactions in the structures of complexes I–III and some their analogues have been considered using molecular Voronoi-Dirichlet polyhedra.     

Interaction of platinum and molybdophosphoric heteropoly acid under conditions of catalyst preparation for benzene oxidation to phenol with an O2-H2 gas mixture

The transformations of platinum and a heteropoly acid (HPA) in binary systems prepared from H₂PtCl₆ or H₂PtCl₄ and H₃PMo₁₂O₄₀ were studied using IR and UV-VIS spectroscopy, elemental analysis, XPS, EXAFS, TPR, and HREM. The calcination of platinum chloride with the HPA to 450°C resulted in the formation of a platinum salt of the HPA along with decomposition products (mixture I). The reduction of calcined samples containing Pt: HPA = 1: 1 with hydrogen at 300°C (mixture II) followed by exposure to air resulted in the regeneration of the HPA structure. The resulting solid samples of Pt _1?n ⁰ Pt _n ^II Cl_mO_xH_y) (H_3+p PMo _12?p ^VI Mo _p ^V O₄₀) (III) contained platinum and molybdenum in both oxidized and reduced states. The following association species were isolated from mixtures I and II by dissolving in water: [Pt _n ^II PMo₁₂O₄₀] (I _s) (n = 0.3?0.8) and [Pt _n ⁰ PMo ₁₂ ^red O₄₀] (II _s) (n ≈ 1). Under exposure to air, the solutions of I _s were stable (pH ～2), whereas Pt^met was released from II _s. After the drying of I _s, the solid association species (Pt _n ^II Cl_mO_xH_y). (H₃PMo₁₂O₄₀), where n = 0.3?0.8, m = 0.2?1, and x = 3?0, (I _solid) were obtained. The I _solid/SiO₂ supported samples were prepared by impregnating SiO₂ with a solution of I _s and drying at 100°C. Platinum metal particles of size ～20 Å and a mixed-valence association species of platinum with the HPA were observed after the reduction of I _solid/SiO₂ with hydrogen at 100–250°C. These samples were active in the gas-phase oxidation of benzene to phenol at 180°C with the use of an O₂-H₂-N₂ mixture.