Crystal structure of a double Np(V) and Co(NH3)63+ maleate, Co(NH3)6[NpO2(HL)2(H2O)3](HL)2?H2O [L = OOC(HC)2COO]

Crystal structure of a double Np(V) and Co(NH₃) ₆ ³⁺ maleate Co(NH₃)₆[NpO₂(HL)₂(H₂O)₃](HL)₂H₂O [L = OOC(HC)₂COO] was studied. The crystal structure consists of complex anions [NpO₂(HL)₂(H₂O)₃]^–, HL^– anions, [Co(NH₃)₆]³⁺ cations, and water molecules of crystallization. Hydrogen bonds in which proton donors are water molecules and hexaamminecobalt cations link structural fragments to form a 3D network. The coordination polyhedra of the Np(V) atoms are pentagonal bipyramids whose equatorial planes are formed by oxygen atoms of two HL^– anions and three water molecules. Four crystallographically independent maleate anions were identified in the structure. Two of these anions enter into the Np(V) surrounding, and their coordination capacity is 1.Translated from Radiokhimiya, Vol. 46, No. 6, 2004, pp. 521–523.Original Russian Text Copyright © 2004 by Charushnikova, Krot, Starikova.     

Crystal Structure of Neptunium(V) Phthalate (NpO2)2(OOC)2C6H4·4H2O

The crystal structure of (NpO₂)₂(OOC)₂C₆H₄·4H₂O [rhombic cell: a = 15.937(3), b = 26.922(5), c = 8.020(2) Å, space group Pbcn, Z = 8, V = 3441.0(12) ų, d _calc = 2.988 g cm^{- 3}, CAD4, MoK , graphite monochromator, 2934 independent reflections; R ₁ = 0.0352, wR ₂ = 0.0951] was studied. The structure consists of NpO₂ ⁺ cations, H₄C₆(COO)₂ ^{2 -} anions, and molecules of coordinated and crystallization water. The crystal lattice involves neutral layers [(NpO₂)₂(OOC)₂C₆H₄(H₂O)₃] _n parallel to the {101} plane. The dioxocations in these layers are bonded to each other to form cationic networks [the Np···Np distance is 3.911(1)-4.202(1) Å]. The coordination polyhedra of Np(1) and Np(2) are pentagonal bipyramids (CN 7). The point group of the neptunyl(V) groups is close to D _h. These groups are bidentate ligands in the cation-cation interaction. The Np = O bond lengths are 1.852(6) [Np(1)-O(1)], 1.849(7) [Np(1)-O(2)], 1.845(7) [Np(2)-O(3)], and 1.841(7) Å [Np(2)-O(4)]; the O = Np = O bond angles are 178.6(3)° [O(2)-Np(1)-O(1)] and 177.4(3)° [O(3)-Np(2)-O(4)]. The equatorial plane of the Np(1) bipyramid consists of two oxygen atoms of adjacent Np(2)O₂ ⁺ dioxocations, two water molecules, and a single oxygen atom of the phthalate anion. The equatorial plane of the Np(2) bipyramid consists of two oxygen atoms of adjacent Np(1)O₂ ⁺ dioxocations, two oxygen atom of the phthalate anion, and a single water molecule. The bond lengths in the equatorial plane of the bipyramid lie in the following ranges: Np-Oyl 2.373(7)-2.437(7) Å (average 2.397 Å) , Np-Ophth 2.360(7)-2.474(7) Å (average 2.431 Å), and Np-Owater 2.534(8)-2.558(9) Å (average 2.544 Å). The phthalate anions are tridentate bridging ligands binding neptunium atoms only within a single cationic network.     

Dynamics of mechanical,acoustical, and electrical properties of epoxy‐amine compositions during cure

Dynamics of mechanical, acoustical, and electric properties is studied in the cure of three samples of polymeric compositions produced on the basis of epoxy oligomer with different content of the curing agent. The measurements were made in a parallel mode with an automated measuring complex. Variations in elastic modules, sound speed, attenuation coefficient, relaxation of the shear stress, electric resistance of the samples during the complete cure in the transition from a liquid into a glass state are considered. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Crystal structure of a Pu(VII) potassium salt,K<Subscript>3</Subscript>PuO<Subscript>4</Subscript>(OH)<Subscript>2</Subscript>·2H<Subscript>2</Subscript>O

A new Pu(VII) compound, K₃PuO₄(OH)₂·2H₂O, was synthesized, and its structure was studied by single crystal X-ray diffraction. This compound is isostructural to the previously described K₃NpO₄(OH)₂·2H₂O. The structure of the latter compound was redetermined to obtain more precise interatomic distances in the NpO₂(OH) ₂ ^3? anion. Changes in An-O bond lengths in the tetragon-bipyramidal coordination polyhedron of the compounds K₃AnO₄(OH)₂·2H₂O in going from Np(VII) to Pu(VII) were considered.     

Neutrophils Mediate Pulmonary Artery Thrombosis In Situ

Pulmonary embolism is a life-threatening condition, which can result in respiratory insufficiency and death. Blood clots occluding branches of the pulmonary artery (PA) are traditionally considered to originate from thrombi in deep veins (usually in legs). However, growing evidence suggests that occlusion of the vessels in the lungs can develop without preceding deep vein thrombosis (DVT). In this work, we used an inferior vena cava (IVC) complete ligation model of DVT in Wistar rats to explore the possibility and mechanisms of PA thrombosis under the conditions where all routes of thrombotic mass migration from peripheral veins are blocked. We demonstrate that rats both with normal and reduced neutrophil counts developed thrombi in the IVC, although, neutropenia caused a substantial decrease in thrombus size and a shift from fresh fibrin toward mature fibrin and connective tissue inside the thrombus. Massive fibrin deposition was found in the PA branches in the majority of DVT rats with normal neutrophil counts, but in none of the neutropenic animals. Neutrophil ablation also abolished macroscopic signs of lung damage. Altogether, the results demonstrate that thrombi in the lung vasculature can form in situ by mechanisms that require local neutrophil recruitment taking place in the DVT setting.     

Crystal structure of uranyl μ3-oxoacetate [(UO2)3(μ3-O)2(OOCCH3)2(H2O)2]

The crystal structure of [(UO₂)₃(₃-O)₂(OOCCH₃)₂(H₂O)₂] consists of uranium coordination polyhedra (CPs) combined via common equatorial edges into ribbons, with ₃-O atoms being common for three CPs. The structure was compared with that of known complexes with ₃-oxo atoms.Translated from Radiokhimiya, Vol. 46, No. 5, 2004, pp. 396–400.Original Russian Text Copyright © 2004 by Charushnikova, Krot, Starikova.     

Synthesis and Crystal Structure of the U(VI) Complex with Triphenylphosphine Oxide {UO2[OP(C6H5)3]4}(ClO4)2

Data on synthesis and structure of the U(VI) complex with triphenylphosphine oxide (TPPO) are presented. Single crystals were grown and the structure of this compound was determined [monoclinic unit cell: a = 9.795(3), b = 25.246(6), c = 14.086(4) Å, = 99.86(2)°, space group P2₁/c, Z = 2, V = 3431.7(15) ų, d _{c a l c} = 1.534 g cm^{- 3}; Siemens P3/PC, MoK radiation, graphite monochromator, /2thetas; scanning, 2947 unique reflections, direct method, R ₁ = 0.0401 for 2261 observed reflections, wR ₂ = 0.1194 for 2947 unique reflections]. The crystal structure consists of complex cations {UO₂[OP(C₆H₅)₃]₄}^{2 +} and ClO₄ ^- anions. The U(VI) atom has a tetragonal-bipyramidal oxygen surrounding with coordination number (CN) 6. The UO₂ group is linear: the O = U = O bond angle is 180.0°, and the U = O bond length is 1.750(6) Å. The square equatorial coordination plane of the bipyramid is formed by oxygen atoms of four TPPO molecules, the U-O_{e q} bond lengths vary from 2.289(6) to 2.307(6) Å (average 2.298 Å), and the O_{e q}-U-O_{e q} bond angles are close to 90°.     

Crystal Structure of U(VI) Peroxo Complex with Triphenylphosphine Oxide {(UO2)2O2[OP(C6H5)3]6}(ClO4)2

The peroxo complex {(UO₂)₂O₂[OP(C₆H₅)₃]₆}(ClO₄)₂ was synthesized, and its crystal structure was determined [triclinic unit cell: a = 10.523(2), b = 16.242(3), c = 16.978(3) Å, = 65.79(3)°, = 85.06(3)°, = 77.14(3)°, space group P-1, Z = 1, V = 2580.1(9) ų, d _{c a l c} = 2.789 g cm^{- 3}; CAD4, MoK , graphite monochromator, direct method, R ₁ = 0.0368 for 3115 observed reflections, wR ₂ = 0.1107 for 4403 unique reflections, 622 refined parameters]. {(UO₂)₂O₂[OP(C₆H₅)₃]₆}(ClO₄)₂ has monomeric structure and consists of the complex cations {(UO₂)₂O₂[OP(C₆H₅)₃]₆}^{2 +} and ClO₄ ^- anions. The uranium atom has a pentagonal-bipyramidal oxygen surrounding (CN 7). Uranyl groups UO₂ ^{2 +} are linear and symmetrical, the U = O bond lengths are 1.780(8) and 1.787(8) Å, the O(1) = U = O(2) bond angles are 178.7(4) Å. The equatorial planes of bipyramids are formed by oxygen atoms of three TPPO molecules [U-O_{T P P O} 2.352(8)-2.368(7) Å, average 2.362 Å] and peroxo group O₂ ^{2 -} [U-O_{p e r} 2.285(8) and 2.323(8) Å, average 2.305 Å]. Two pentagonal bipyramids sharing the common edge O(3)-O(3)^(a) form the centrosymmetrical peroxo-bridged diuranyl complex {(UO₂)₂O₂[OP(C₆H₅)₃]₆}^{2 +} with the [UO₂O₂UO₂]^{2 +} core. The length of the O(3)-O(3)^{( 9a )} edge is 1.426(15) Å.     

Highly Stereoselective Synthesis of Novel Multistereogenic Bis‐Bifunctional Ligands Based on [2.2]Paracyclophane‐ 4,7‐quinone,their Structure Elucidation and Application in Asymmetric Catalysis

Bis‐bifunctional cis‐4,7‐diarylsubstituted‐4,7‐dihydroxy‐4,7‐dihydro[2.2]paracyclophanes 3–6 were synthesized by a highly diastereoselective reaction of ortho‐substituted aryllithium reagents with [2.2]paracyclophane‐4,7‐quinone ( 1 ). Enantiomerically pure diols 3–5 were tested as chiral inductors in the enantioselective addition of diethylzinc to benzaldehyde (up to 93.5% ee). Acid dehydration of cis‐4,7‐di(2‐methoxyphenyl)‐4,7‐dihydroxy‐4,7‐dihydro[2.2]paracyclophane ( 3 ) results in 4,7‐dihydro‐7,8‐di(2‐methoxyphenyl)[2.2]paracyclophane‐4‐one ( 8 ) – a planar chiral cyclohexadienone of the [2.2]paracyclophane series with a para‐semiquinoid substructure. X‐Ray investigations of compounds 3, 4 and 8 were performed.