[en] Sodium triaqua[(1,2-ethanediyldinitrilo-κ²N,N')tetraacetato-κ⁴O¹,O²,O³ ,O⁴]lanthanate(III) pentahydrate, Na[La(C₁₀H₁₂N₂O₈)(H₂O)₃].5H₂O, sodium t triaqua[(1,2-ethanediyldinitrilo-κ²N,N')tetraacetato-κ⁴O¹,O²,O³ ,O⁴]-neodymate(III) pentahydrate, Na[Nd(C₁₀H₁₂N₂O₈)-(H₂O)₃].5H₂O, and sodium triaqua[(1,2-ethanediyldinitrilo-κ²N,N')tetraacetato-κ⁴O¹,O²,O³ ,O⁴]europate(III) pentahydrate, Na[Eu(C₁₀H₁₂N₂O₈)(H₂O)₃].5H₂O, are isomorphous and isostructural; all contain nine-coordinate lanthanoid ions, each of which bonds to two N atoms, four acetate O atoms and three water molecules. (orig.)

[en] The complexes of the type Cs₂MCl₄ (where M = Fe, Co, Ni, Cu, Zn and Mg) have distorted tetrahedral structure. Varied distortion from regular tetrahedral geometry is due to the covalent bonding between Cs-Cl. The species [MCl₄]^2- ions act as double faced bidentate ligands. The structure has been substantiated by IR spectra and crystal structure data. (author). 14 refs., 3 tabs

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[en] μSR spectra from a metal carbonyl compound are reported for the first time. The metal cluster compound Cs₂[Os₁₀C(CO)₂₄] shows a temperature dependent signal for implanted muons with the onset of motional narrowing at ca. 200 K. Also observed is a probable change in the width within the temperature range 40-140 K. A tentative assignment is provided for the muon sites. (orig.)

[en] The new compounds LiK[C(CN)₃]₂ and Li[C(CN)₃] . 1/2 (H₃C)₂CO were synthesized and their crystal structures were determined. Li[C(CN)₃] . 1/2 (H₃C)₂CO (H₃C)₂CO crystallizes in the orthorhombic space group Ima2 (no. 46) with the cell parameters a=794.97(14), b=1165.1(2) and c=1485.4(3) pm, while LiK[C(CN)₃]₂ adopts the monoclinic space group P2₁/c (no. 14) with the cell parameters a=1265.7(2), b=1068.0(2) and c=778.36(12) pm and the angle β=95.775(7) . Single crystals of K[C(CN)₃] were also acquired, and the crystal structure was refined more precisely than before corroborating earlier results.

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[en] This work deals with the study of norbadione A, a pigment extracted from mushrooms and known to complex cesium cations. The study of the acid-base properties of norbadione A has allowed to determine the relative acidity of the seven protonable functions of the molecule and to reveal a reversible isomerization of the double exocyclic bond of the pulvinic moieties. The observed change of configuration is induced by a hydrogen bond of the H-O-H type and by electrostatic interactions. Moreover, the microscopic protonation mechanism of the norbadione A has been analyzed, considering three different study media where the acid-base properties of the norbadione A are compared. In the presence of 0.15 mol.l^-1 of NaCl, it has been observed a remarkable cooperativity in the protonation of the enol groups. At last, the use of different analytical methods (NMR, potentiometry and calorimetry) has allowed to study the complexing properties of the norbadione A towards cesium and other alkaline and rare earth cations. (O.M.)

[en] The results of ab initio electronic structure calculations on the C₆₀ cage and its endohedral (''inside-the-cage'') complexes with F^-, Ne, Na⁺, Mg²⁺, and Al³⁺ are presented. Placing the ions at the center of the cage results in a net stabilization and screening of the charges. The ionic guests either decrease (F^-) or increase (Na⁺, Mg²⁺, and Al³⁺ ) the cage radii. The complexes with the ions at the cage center are local maxima with respect to the displacement of the guests. The C₆₀·Ne complex, which is destabilized by ca. 0.4 kcal/mol relative to the separated components, is an energy minimum. In the C₆₀·Na⁺ complex, the energy minimum (which lies only 0.8 kcal/mol below the maximum) corresponds to the Na atom displaced by 0.66 A from the cage center. The calculated properties of the endohedral complexes are easily rationalized with a model involving a double-layer polarizable C₆₀ cage affected by the electrostatic potential produced by the enclosed guests