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| 2. |
- Farkas, I., et al.
(author)
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Crystal structure of the sodium salt of the uranyl-oxyacetate-fluoride dimer, Na4(UO2)2(OCH2COO)2F 4 · 6H2O
- 1999
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In: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X .- 1902-3103. ; 53:11, s. 1009-1012
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Journal article (peer-reviewed)abstract
- The structure of the ternary uranyl-oxyacetate-fluoride dimer, (UO2)2(OCH2COO)2F4 4-, was studied by single crystal X-ray diffraction. The space group is P1̄, and the structure contains discrete dimers with a double pentagonal bipyramid geometry, linked by octahedrally coordinated sodium ions. The uranyl ion has a coordination number of five with two fluorides and three oxygens coordinated in a plane perpendicular to the linear UO2 axis. The dimer is formed via bridging oxygen atoms from the deprotonated hydroxyl groups of the glycolate ligands.
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| 3. |
- Huang, J H, et al.
(author)
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Phase relations and activities of (Mn,Ni)-olivine solid solution in the ternary system MnO-NiO-SiO2
- 1996
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In: Acta Chemica Scandinavica. - 0904-213X .- 1902-3103. ; 50:12, s. 1102-1107
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Journal article (peer-reviewed)abstract
- Phase relations involving tie-lines between (Mn, Ni)O and (Mn, Ni)(2)SiO4 solid solutions in the ternary system MnO-NiO-SiO2 have been studied experimentally at 1310 K. A great number of mixtures, with various constitutions, were equilibrated and the compositions of coexisting solid-solution phases were determined by inductively coupled plasma (ICP) analysis as well as X-ray d-spacing measurements. The olivine phase (Mn-1-y,Ni-y)(2)SiO4 and SiO2 occur together at compositions 0.27 less than or equal to y less than or equal to 1, and the pyroxene phase (Mn-1-z, Ni-z)SiO3 exists only in the composition range 0 less than or equal to z less than or equal to 0.08. The activities in the (Mn, Ni)-olivine solid solution were derived from the tie-line data obtained at 1310 K. By using the solid-state EMF method, the activities of Ni-olivine solid solution were also determined at several compositions, 0.27 less than or equal to y less than or equal to 1, in the temperature range 1140-1395 K. The activities obtained from both methods show significant positive deviations from ideality.
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| 4. |
- Karlsson, M, et al.
(author)
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Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution. 33. The Al(methylmalonate)(2)(H2O)(2)(-) complex crystallised as a double salt with Al(H2O)(6)(3+) and Cl-
- 1998
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In: Acta Chemica Scandinavica. - 0904-213X .- 1902-3103. ; 52:8, s. 995-999
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Journal article (peer-reviewed)abstract
- The crystal structure of hexaaquaaluminium(III) trans-diaquabis(2-methylpropanedionate)aluminate(III) dichloride tetrahydrate, [Al(H2O)(6)(3+)] [Al(C4H4O4)(2)(H2O)(2-)][Cl-](2 .)4H(2)O, was determined by single-crystal X-ray diffraction. The compound crystallises in the triclinic space group , with a = 6.956(1), b = 8.413(2), c = 10.737(2) Angstrom, alpha = 89.78(2), beta = 106.90(2), gamma = 95.25(2)degrees and Z = 1. The refinement of 148 parameters on 2563 reflections [I > 2.0 sigma(I)] gave a final R-value of 0.076 (R-w = 0.052, S = 1.082). The double salt was crystallised from aqueous solution and contains two different octahedral aluminium complexes, an Al(H2O)(6)(3+) complex and an AlL2(H2O)(2)(-) complex with two methylmalonate ions equatorially coordinated and with two molecules of water at the apices. The structure is built up from layers of the Al complexes alternated with layers of chloride ions and water molecules parallel to the (010) plane.
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| 5. |
- Karlsson, M, et al.
(author)
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Equilibrium and structural studies of silicon(IV) and aluminium(III) in aqueous solution. 34. A crystal structure determination of the Al(methylmalonate)(2)(CH3OH)(2)(-) complex with Na+ as counter-ion
- 1998
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In: Acta Chemica Scandinavica. - 0904-213X .- 1902-3103. ; 52:9, s. 1116-1121
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Journal article (peer-reviewed)abstract
- The crystal structure of sodium bis(trans)-2-methylpropanedionatedimethanolaluminate(III), [Na+][Al(C4H4O4)(2)(CH3OH)(2)(-)], has been determined by single crystal X-ray diffraction. The compound crystallises in the trigonal space group R (3) over bar, with a = 12.046(2), c= 28.705(6) Angstrom and Z= 9. The refinement of 103 parameters on 946 reflections [1>2.0 sigma(I)] gave a final R-value of 0.064 (R-w= 0.066, S= 1.000). The structure consists of octahedral Al(C4H4O4)(2)(CH3OH)(2)(-) complexes and sodium ions. In these complexes, methylmalonate coordinates to Ak(3+) bidentately in the equatorial plane of the octahedron, while methanol coordinates at the apices. As such, it represents a rare single-crystal example of direct aluminium( III)-methanol coordination. The complexes, arranged in layers, are connected to each other by octahedrally coordinated sodium ions, in special position 6c, and hydrogen bonds. The layers, with the methyl group of methylmalonate pointing out from the layers, are stacked perpendicular to the [001] direction and are held together by other octahedrally coordinated sodium ions, in special position 3b.
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| 7. |
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| 8. |
- Lyxell, D G, et al.
(author)
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Multicomponent polyanions .48. The crystal structure of trihydrogen dodecamolybdophosphate-benzene(1/3)
- 1996
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In: Acta Chemica Scandinavica. - 0904-213X .- 1902-3103. ; 50:11, s. 985-990
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Journal article (peer-reviewed)abstract
- A novel organic solvated heteropoly compound, H3Mo12PO40. 3(C6H6), crystallised in the monoclinic form, P2(1)/n (No. 14), with a = 12.189(2), b = 13.981(2), c = 12.978(1) Angstrom and beta = 98.59(1)degrees. The refinement of 340 parameters with 3705 reflections [I > 3.0 sigma(I)] gave a final R-value of 0.061 (R(w) = 0.067). The polyanion, having a so-called alpha-Keggin structure, is disordered around an inversion centre. One of three benzene molecules is sandwiched between polyanions, and the other two are accommodated in a cavity surrounded by polyanions. The links between polyanions and benzene rings are mainly due to hydrogen bonds. The phosphate and benzene in the compound were formed by hydrolysis of phenylphosphonate. (C) Acta Chemica Scandinavica 1996.
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| 9. |
- Lyxell, D G, et al.
(author)
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Multicomponent polyanions. 54. Crystal structure of tetracaesium monohydrogen phosphato(phosphito)pentamolybdate dihydrate, Cs-4[H(HP)PMo5O22]center dot 2H(2)O
- 1998
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In: Acta Chemica Scandinavica. - 0904-213X .- 1902-3103. ; 52:4, s. 425-430
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Journal article (peer-reviewed)abstract
- The crystal structure of tetracaesium monohydrogen phosphato (phosphito)pentamolybdate dihydrate was determined by single-crystal X-ray diffraction. The compound crystallises in the triclinic space group P (1) over bar, a=10.284(2), b= 10.791(2) and c=13.047(3) Angstrom, alpha=109.34(2), beta=99.92(2) and gamma=102.85(2)degrees, V=1283.4(5) Angstrom(3) and Z=2. The final R-values are R=0.066, wR=0.039 and S=1.3667. The H(HP)PMo5O224- anion has common features with the Strandberg X2M5-type heteropolyanion. The five MoO6 octahedra form a five-membered ring by one corner-sharing and four edge-sharing connections, and the tripodal phosphate and phosphite ligands protrude from each side of this ring in opposite directions. This is the first example of the structure of the heteropolyoxometalate having both P-III and P-V as heteroatoms.
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| 10. |
- Marton, J., et al.
(author)
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Isomerization reactions of 7-substituted 6,14-bridged thebaine derivatives (Bentley compounds)
- 1998
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In: Acta Chemica Scandinavica. - : Danish Chemical Society. - 0904-213X .- 1902-3103. ; 52:10, s. 1234-1238
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Journal article (peer-reviewed)abstract
- Equilibration of the 7α→7β isomers of 7-subslituted 6,14-ethenomorphinanes has been accomplished, for the first time, in dipolar aprotic solvents by the application of bases with weak nucleophilic character. Transformation of the 7β-nitrile with phenylmagnesium bromide led to a new type of 6,6′-dimeric compound.
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