Über Salze und Doppelsalze der Seltenen Erden, 3. Mitt.

Complexes of the type Cs[Ln(SO₄)₂(H₂O)₃]H₂O, (Ln=La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were prepared from aqueous solution. The compounds are all isomorphous and crystallise monoclinic, space group P2₁/c,Z=4. Unit cell parameters were determined by the single crystal technique and correlated to the ionic radii of Ln³⁺.IR spectra were recorded in the range 4000-250 cm^–1 and tentatively assigned. The number of observed bands exceeds the predicted number by site symmetry selection rules, indicating coupling in the layer structure.

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2. Mitt.     

Synthesis and characterization of hydrazinium(2+) tetrafluoroborate(III)

The reaction between hydrazinium(2+) fluoride and boron trifluoride in anhydrous hydrogen fluoride yielded slightly soluble hydrazinium(2+) tetrafluoroborate. It was characterized by chemical analysis, vibrational spectra and thermal analysis. An X-ray diffraction study showed that crystals of N₂H₆(BF₄)₂ are triclinic, space group P$\text{1}$ (No. 2). There are discrete N₂H²⁺₆ and BF^?₄ units in the crystals interlinked by hydrogen bonds of the type NH…F..     

Crystal-structure and Mössbauer studies of Li1.746Nd4.494FeO9.493

The Li_1.746Nd_4.494FeO_9.493 (LNF) ternary phase, located in the Li₂O-rich part of the Li₂O-Nd₂O₃-Fe₂O₃ system, crystallizes with a cubic unit cell of dimension and the space group Im3m. Refinement on F resulted in R=1.9%. The structure is comprised of a network of corners, edges and faces sharing the coordination polyhedra of neodymium. In between this skeleton the regular octahedra of oxygen-coordinated iron and trigonal prisms of lithium are located. The Mössbauer spectra revealed the presence of Fe³⁺, Fe⁴⁺ and Fe⁵⁺ ions distributed on two symmetry-independent lattice positions.     

Some fixed point theorems for non-self mappings of contractive type with applications to endpoint theory

In this paper, in the setting of complete metric spaces we establish some fixed point theorems for non-self mappings of contractive type satisfying either the Reich–Zaslavski property or the approximate fixed point property. As applications, we obtain some results in endpoint theory.     

新型碱性离子液体催化剂高效催化合成吡喃酮[2,3-d]嘧啶酮和[2,3-d]嘧啶衍生物

制备了碱性离子液体1,1'-(丁烷-1,4-二基)双(1,4-二氮杂二环[2.2.2]辛烷-1-ium)羟化物,并采用红外光谱、1H核磁共振谱和pH值分析对其进行了表征.然后将它用于室温研磨条件下高效催化合成吡喃酮[2,3-d]嘧啶酮和[2,3-d]嘧啶.该法步骤简单,反应时间短,产物收率高,无需柱色谱分离,原料易得,且可回收利用.     

Efficient Synthesis of Novel Thiazol‐2‐ylidene‐amides Using Carbonylthiourea Building Blocks

In this work, an efficient and versatile synthesis of novel thiazol‐2‐ylidene‐amides from various carbonylthiourea derivatives is described. A sequential alkylation–cyclization reaction between thioureas and propargyl bromide in the presence of DABCO in refluxing ethanol afforded 4‐methylthiazol‐2(3H)‐ylidene‐amide derivatives in good yields.     

Extending the Domain‐Averaged Exchange‐Correlation Energies Within the Context of the MC‐QTAIM: Tracing Subtle Variations Induced by Isotope Substitution

Recently, it has been demonstrated that the domain‐averaged exchange‐correlation energies, V^xc, are capable of tracing the covalent character of atom–atom interactions unequivocally and thus pave the way for detailed bonding analysis within the context of the quantum theory of atoms in molecules (QTAIM) [M. García‐Revilla, E. Francisco, P. L. Popelier, A. Martín Pendás, ChemPhysChem 2013 , 14, 1211–1218]. Herein, the concept of V^xc is extended within the context of the newly developed multicomponent QTAIM (MC‐QTAIM). The extended version, , is capable of analyzing nonadiabatic wavefunctions and thus is sensitive to the mass of nuclei and can trace “locally” the subtle electronic variations induced by isotope substitution. To demonstrate this capability in practice, ab initio nonadiabatic wavefunctions for three isotopically substituted hydrogen cyanide molecules, in which the hydrogen nucleus was assumed to be a proton, deuterium, or tritium, were derived. The resulting wavefunctions were then used to compute and it emerged that for the hydrogen–carbon bond, the was distinct for each isotopic composition and varied in line with chemical expectations. Indeed, the introduction of paves the way for the investigation of vast numbers of structural and kinetic isotope effects within the context of the MC‐QTAIM.