Crystal and Molecular Structure of a New Complex of [60]Fullerene, 2(C60)·2(TMTSF)·(C6H6)

Abstract

A new molecular complex of [60]fullerene with composition 2(C₆₀)·2(TMTSF)·(C₆H₆) was synthesized. The structure and composition of the complex were found by an x-ray study. Crystal data: 2(C₆₀)2(C₁₀H₁₂Se₄)(C₆H₆), M = 2415.4, monoclinic, a = 19.388(4), b = 13.410(2), c = 32.467(6) A, β = 92.71(2)°, V = 8432(3) [Adot]³, space group P2₁/n, Z = 4, d_calc = 1.903 g/cm³, R = 0.0606. The crystal structure was shown to be layered with the alternating layers of three types. Two of them have the same composition (C₆₀, TMTSF) but different interorientation of molecules in a layer and different number of shortened contacts C…C and C…Se. The third layer consists of benzene molecules. The energy of intermolecular interactions C₆₀…. TMTSF was estimated by ab initio calculations. The TMTSF molecule has a “boat” conformation.     

Synthesis and Study of Sr[HSiUO6]2·2H2O and Ba[HSiUO6]2·2H2O

Uranosilicates of the general formula M^{I I}[HSiUO₆]₂·2H₂O (M^{I I} = Sr, Ba) were prepared by hydrothermal synthesis. Previously unknown intermediate crystal hydrates were separated and studied by X-ray diffraction (XRD), IR spectroscopy, and thermal analysis. Polymorphic transitions -Sr[HSiUO₆]₂ -Sr[HSiUO₆]₂ and -Ba[HSiUO₆]₂ -Ba[HSiUO₆]₂ were revealed at 700 and 780°C, respectively.     

Complexes with substituted 2,5-dihydroxy-p-benzoquinones: The inclusion compounds [Y(H2O)3]2 (C6Cl2O4)3·6.6H2O and [Y(H2O)3]2 (C6Br2O4)3·6H2O

Single crystal of [Y(H₂O)₃]₂ (C₆Br₂O₄)₃·6H₂O and [Y(H₂O)₃]₂ (C₆Cl₂O₄)₃·6.6H₂O were grown in aqueous silicagel. The compounds are in principle isostructural. In Y chloranilate one additional water site is occupied as verified by X-ray single crystal structure analysis. Y³⁺ is nine-coordinated by three water molecules and six oxygen atoms of the bischelating (C₆X₂O₄)²⁻ ions (XCl, Br). The coordination polyhedron is an only slightly distorted tri-capped trigonal prism. The connection of Y³⁺ with the dianions leads to infinite, corrugated layers. The layer stacking yields cage-like cavities in which water molecules are accomodated. Hydrogen bonds interlink adjacent layers. Further hydrogen bonds involve the entrapped water molecules. DSC measurements indicated a complicated dehydration process which caused right at the start destruction of the single crystals.     

Bromination of [60]Fullerene. I. High‐Yield Synthesis of C60Br x (x=6, 8, 24)

Abstract

The systematic study of the bromination of C₆₀ was performed under various experimental conditions. Application of some chloroarenes as reaction media resulted in the high‐yield (70–96%) selective synthesis of C₆₀Br₆ and C₆₀Br₈. Direct bromination of fullerene yielded either C₆₀Br₈, C₆₀Br₁₄, or C₆₀Br₂₄ depending on the reaction time. Possible pathways of bromination of C₆₀Br₈ were analyzed using semiempirical (AM1) calculations, two most probable molecular structures are conjectured for the first isolated C₆₀Br₁₄.     

Molecular Complex of [60]Fullerene with 2-(4-thione-l,3-dithiolan-5-yliden)-4,5-dimethyl-1,3-diselenol [C60·2(DTDS)]: Synthesis,Crystal Structure and Properties

Abstract

New molecular complexes of [60]fullerene with 2-(4-thione-l,3-dithiolan-5-yliden)-4,5-dimethyl-l,3-diselenol [C₆₀·2(DTDS)] have been synthesized, crystal structure, IR spectral and electrochemical properties have been studied. Partial charge transfer has been found. An unusual shortening of the endocyclic S-C(sp²) bond in the DTDS molecule has been found to be stipulated by conformational vibrations of the >CH₂ group. A comparative analysis of the X-ray data for the [C₆₀·2(DTDS)] crystals and the quantum chemical calculations (SCF MO, 6-31G? basis) for the DTDS molecules and its radical ions showed charge transfer not to be the cause for the shortening of the exocyclic C=S bonds.     

Complexes with substituted 2,5-dihydroxy-p-benzoquinones: AE[C6(C2H5)2O4]·3H2O (AE=Ca,Sr, Ba)

Single crystals of AE[C₆(C₂H₅)₂O₄]·3H₂O belonging to space group P2₁2₁2₁ were grown in aqueous silicagel (AE=Ca, Sr) and in aqueous solution (AE=Ba), respectively. AE²⁺ is coordinated by four oxygen atoms of two bis-chelating [C₆(C₂H₅)₂O₄]²⁻ ions, thus forming infinite, corrugated chains extending along [010]. The coordination polyhedron is completed by additional water molecules. The coordination sphere is different for the three different AE²⁺ ions yielding CN increasing from Ca²⁺ to Ba²⁺. The principle features of the crystal structure, however, remain unchanged. Adjacent chains are interlinked by hydrogen bonds between water molecules of the coordination sphere and the oxygen atoms of the [C₆(C₂H₅)₂O₄]²⁻ ion.     

Synthesis and characterization of a new organic sulphate, [2,3-(CH3)2C6H3NH3]HSO4·H2O

Crystals of a new hybrid compound C₈H₁₂N⁺, HSO₄^?·H₂O were synthesized in aqueous solution and characterized by X-ray diffraction and IR absorption spectroscopy. This compound crystallizes in the orthorhombic non-centrosymmetrical space group P2₁2₁2₁ and an unit cell with a = 5.74(2) Å, b = 9.17(2) Å, c = 21.34(4) Å, V = 1124(6) Å³, and Z = 4. Its crystal structure is a packing of alternated inorganic and organic layers parallel to (a,b) planes. The different components are connected by a bi-dimensional network of strong OH…O and NH…O hydrogen bonds. Then, in order to detect phase transitions and watch changes in the conductivity behaviour, investigations by DTA–TG and differential scanning calorimetry (DSC) and electrical conductivity measurements were carried out.     

Synthesis and Study of Uranium-Containing Aluminum Compounds Al[BVUO6]2[OH]·nH2O (BV = P,As)

A procedure was developed for preparing aluminum hydroxouranophosphate and hydroxourano- arsenate. The structural features and thermal decomposition pathways of the compounds were studied by X-ray diffraction, IR spectroscopy, and thermal analysis.     

Interaction of U(VI), Np(VI), Pu(VI), and Np(V) with benzenetricarboxylic acids: Complexation in aqueous solutions, synthesis, and crystal structure of uranyl complexes [UO2(H2O)2{C6H3(COO)2(COOH)}]2·2H2O and [(UO2)3(H2O)4{C6H3(COO)3}2]

The complexation of U(VI), Np(VI), and Pu(VI) and of Np(V) with 1,2,3- and 1,2,4-benzenetricarboxylic acids (BTC) in aqueous solutions was studied in wide ranges of pH and actinyl ion concentrations. The compositions of the forming hexavalent actinide complexes were determined. Their apparent stability constants β₁′ depend on pH of the solution: in the pH range 2–4, logβ₁′ from 2 to 4 for the complexes of U(VI), Np(VI), and Pu(VI) with 1,2,3-BTC and from 1.5 to 3.5 for the complexes with 1,2,4-BTC. For Np(V), the β₁′ values are close with both acids, and at equal pH values the Np(V) complexes are less stable than the An(VI) complexes (An = U, Np, Pu). With an increase in pH from ～3 to 6.2–6.9, logβ₁′ of the Np(V) complexes increases approximately from 0.5 to 3. Solid U(VI) complexes with 1,2,3- and 1,2,4-benzenetricarboxylic acids were synthesized by the hydrothermal method, their crystal structure was determined, and the IR spectra were examined.     

Synthesis, Physicochemical Properties, and Electrode Behavior of Ni2[Ni(OH)6W6O18 ] · 8H2O

Nickel(II) hexatungstonickelate(II) was synthesized and characterized by elemental analysis, x-ray diffraction, thermal analysis, IR spectroscopy, and ¹H nuclear magnetic resonance. The results demonstrate that constitutional water is present in the form of OH groups, which can be removed by heating to 230–370°C. The chemical formula of the compound is Ni₂[Ni(OH)₆W₆O₁₈] · 8H₂O. Nickel(II) hexatungstonickelate(II), a poorly soluble compound, was tested as an electrode for Ni(II) determination in solution. Its electrode properties and selectivity for other ions suggest that it is a promising material for such applications. At pH 5, the ion-selective electrode we fabricated has a Nernstian response to Ni(II) (10^–5 to 10^–1 mol/l) which is close to that predicted theoretically.     

Synthesis of Tyr-Pro-Phe-Val-Glu-L-[3,4-3H]Pro-Ile,Tyr-D-Ala-Phe-Gly-Tyr-L-[3,4-3H]Pro-Ser-NH2, and Tyr-D-Ala-Phe-Gly-Tyr-D-[3,4-3H]Pro-Ser-NH2, Labeled Analogs of Human β-Casomorphin and Dermorphin

Analogs of human -casomorphin and dermorphin, unsaturated in the proline unit, were prepared. Procedures were developed for tritium labeling of these peptides. It was advantageous to introduce the label before deprotection, since in this case the reaction can be performed in an aprotic solvent. Tritiation before deprotection ensured 5-6 times higher molar radioactivity of the products.     

Synthesis and structure of Cs3[UO2(CH3COO)3]2(NCS)·H2O

The compound Cs₃[UO₂(CH₃COO)₃]₂(NCS)·H₂O (I) was synthesized and studied by IR spectroscopy and single crystal X-ray diffraction. Compound I crystallizes in the monoclinic system with the following unit cell parameters: a = 7.8286(9), b = 19.892(2), c = 20.050(2) Å, β = 94.527(2)°, space group P2₁/c, Z = 4, R = 0.0387. The uranium-containing structural units in crystals of I are mononuclear complexes [UO₂(CH₃COO)₃]^? belonging to crystal-chemical group AB ₃ ⁰¹ (A = UO ₂ ²⁺ , B⁰¹ = CH₃COO^?) of uranyl complexes.     

Crystal Structure of An(VI) Complexes with Succinate Anions, [PuO2(C4H4O4)(H2O)] and Cs2[(AnO2)2(C4H4O4)3]·H2O (An = U,Np, Pu)

Radiochemistry - Actinide(VI) complexes with succinate anions [PuO2(succ)(H2O)] and Cs2[(AnO2)2(succ)3]·H2O (An = U, Np, Pu), where succ = [C4H4O4]2 ?, were synthesized and studied by...     

X-ray powder diffraction and IR study of NaMg(H2O)2[BP2O8]·H2O and NH4Mg(H2O)2[BP2O8]·H2O

NaMg(H₂O)₂[BP₂O₈]·H₂O was prepared by hydrothermal synthesis and was characterized by X-ray powder difraction and IR method. The title compound was synthesized from MgCl₂·6H₂O, NaBO₃·4H₂O, and (NH₄)₂HPO₄ with variable molar ratios using hydrothermal method by heating at 165 °C for 3 days. The X-ray powder diffraction data was indexed in hexagonal system, the unit cell parameters were found to be as a = 9.428, c = 15.82 Å, Z = 4 and the space group is P6₁22. It is isostructural with M^lM^ll(H₂O)[BP₂O₈] type compounds where M^l = Na, K; M^ll = Mg, Mn, Fe, Co, Ni and Zn. In addition NH₄Mg(H₂O)₂[BP₂O₈]·H₂O was also synthesized the first time in this research. Its unit cell parameters and hkl values were in good agreement with the sodium magnesium compound. The unit cell parameters are a = 9.529, c = 15.736 Å. The indexed X-ray powder diffraction data of both compounds which were not reported in the literature is presented in this work. The IR data of NaMg(H₂O)₂[BP₂O₈]·H₂O is also reported.     

Crystal structure of mixed-valent Np(IV)/Np(V) chloride, [Np(NpO2)6(H2O)8(OH)Cl9]·H2O

A new mixed-valent Np(IV)/Np(V) chloride, [Np(NpO₂)₆(H₂O)₈(OH)Cl₉]·H₂O, was synthesized, and its crystal structure was determined. The crystals consist of NpO ₂ ⁺ and Np⁴⁺ cations, of Cl^? and OH^? anions, of coordination-bonded water molecules, and of water molecules of crystallization. The Np(V) atom, Np(1), has pentagonal bipyramidal coordination surrounding with O atoms in the apical position and with the equatorial plane formed by three Cl^? anions, O atom of the adjacent NpO ₂ ⁺ cation, and O atom of water molecule. The mutual coordination of the neptunyl(V) ions, cation-cation (CC) interaction, links the Np(1) coordination polyhedra via common vertices into rings around sixfold axes, with the Np(V)?Np(V) distance in these fragments of 4.276 Å. The ring fragments are linked with each other via common equatorial edges of the bipyramids into layers perpendicular to c-axis. The Np(IV) atom, Np(2), has coordination surrounding in the form of tricapped trigonal prism (CN 9) with the tetragonal lateral faces formed by the O atoms of the NpO ₂ ⁺ cations and the capping positions occupied by the O atoms of two water molecules and one hydroxy group. The Np(2) atoms act in CC interactions as coordination center for six NpO ₂ ⁺ ions, with the Np(IV)?Np(V) distance of 4.183 Å. The Np(2) polyhedra are arranged in the crystal between layers of the Np(1) coordination polyhedra, linking them with each other.     

Hydrothermal Crystallization in the Systems LiOH–MO2–GeO2–H2O (M = Ti, Sn) at 500°C and 0.1 GPa: Li2Ti[5]Ge[4]O5 and Li2Ge[6]Ge2 [4]O6 Phase Relations

Crystallization in the LiH–Ti₂–Ge₂–H₂O and LiOH–SnO₂–GeO₂–H₂O hydrothermal systems was studied at 500°C and 0.1 GPa. The phases crystallizing in the Ti system are Li₂Ti^[5]Ge^[4]O₅, Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂, Li₃HGe₄ ^[6]Ge₃ ^[4]O₁₆ · 4H₂O, and Li₂Ge^[4]O₃ (Ge in four- or sixfold oxygen coordination, and Ti in fivefold oxygen coordination). Over a wide range of TiO₂ : GeO₂ molar ratios (6 : 1 to 1 : 1), the dominant phase is Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂. At higher GeO₂ contents (TiO₂ : GeO₂ = 1 : 2 to 1 : 6), both Li₂Ti^[5]Ge^[4]O₅ and Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂ crystallize. The crystallization fields of Ge-containing phases at TiO₂ : GeO₂ = 1 : 2 to 1 : 6 are (in order of increasing LiOH concentration) GeO₂ (rutile structure), Li₂Ti^[5]Ge^[4]O₅ + Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂, and Li₂Ti^[5]Ge^[4]O₅ + Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂ + Li₂Ge^[4]₃ + Li₃HGe₄ ^[6]Ge₃ ^[4]O₁₆ · 4H₂O. The phases crystallizing in the Sn system are Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂, Li₃HGe₄ ^[6]Ge₃ ^[4]O₁₆ · 4H₂O, and Li₂Ge^[4]O₃. Tin is present in the form of SnO₂ only. The structures of Li₂Ti^[5]Ge^[4]O₅ and Li₂Ge^[6]Ge₂ ^[4]O₆(OH)₂ are characterized by the simplest type of matrix assembly: direct packing of substructural precursor units and their two-dimensional growth in various crystallographic directions.     

Synthesis,Characterization, and X-ray Structure of Tetraaminoguanidinium Diuranyl Tetraoxalate Monohydrate (HAgun)4[(UO2)2(C2O4)4]·H2O

Radiochemistry - A new uranyl oxalate complex containing aminoguanidinium cation was isolated from an aqueous solution containing uranyl nitrate hexahydrate, oxalic acid dihydrate, and...     

Mixed-Cation Molybdate Complex of Neptunium(V), Li2Na[NpO2(MoO4)2]·4H2O

Radiochemistry - A new mixed-cation complex Li2Na[NpO2(MoO4)2]·4H2O with NpO2+ : MoO42– = 1 : 2 has been synthesized and structurally characterized. The coordination environment of Np(V)...     

Synthesis,characterization and crystal structure of a novel Strandberg-type polyoxoselenomolybdate Rb4[Se2Mo5O21]·2H2O

An inorganic compound formulated as Rb₄[Se₂Mo₅O₂₁]·2H₂O (1) has been isolated by conventional solution method and structurally characterized by single-crystal X-ray diffraction methods, scanning electron microscopy (SEM), powder XRD, IR, UV–vis spectra, and cyclic voltammetry measurements. This compound crystallizes in the monoclinic system, space group C2 with unit a = 19.701 (3) Å, b = 10.296 (2) Å, c = 12.134 (4) Å, β = 106.96 (2)° and Z = 4. The crystal structure of (1) is built up from a Strandberg clusters connected through hydrogen-bonding interactions into a three-dimensional supramolecular network.