Jože Šiftar

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.

IR- und Raman-Spektren einiger Kaliumpentafluorometallate-monohydrate

The IR- and Raman Spectra of several compounds of the stoichiometryM2IMIIIF5H2O and their deuterated analogs have been interpreted on the basis of their crystal structures. The compounds studied were divided into two classes regarding the bonding of water molecules. The main spectroscopic difference between the two classes was found in the region of H2O vibrations in good agreement with theoretical predictions. The metal—fluorine and metal—oxygene vibrations gave no direct information concerning the two types of water.

IR-Spektren einiger wasserfreien fluoro-aluminate,-gallate und -indate

IR spectra of several hexa-, penta-and tetra-fluoro-metal-lates of aluminium, gallium and indium with several univalent cations together with hydrazinium(+1 and+2) were recorded from 4000 to 59 cm−1. Site group and factor group vibrational analysis was performed for the compounds with known structures. Complete agreement between theory and experiment was found only in the case of tetragonal tetrafluorometallates. No splittings of the valence and deformation modes were observed with hexafluorometallates even in the caseof low symmetry. Splitting is characteristic for penta-and tetrafluoro compounds. In the case of hydrazinium fluorometallates octa-hedral coordination was additionaly proved on the basis of position of absorption bands. Weak hydrogen bonds were used for the explanation of the spectra of ammonium ion in the corresponding compounds.ZusammenfassungHexa-, Penta-und Tetra-fluorometallate von aluminium, Gallium, Indium, einigen einwertigen Ionen und von Hydrazinium(1+ und2+) wurden im Spektralbereich von 4000 bis 59 cm−1 untersucht. Für die Verbindungen mit bekannten Strukturen wurden die Faktorgruppenanalyse und Vibrations-analyse auf Grund der Lagesymmetrie ausgeführt. Vollkommene Übereinstimmung zwischen den theoretischen und experimentellen Daten ergibt sich nur bei den tetragonalen Tetrafluorometallaten. Bei Hexafluorometallaten erscheint bei niedrigeren Symmetrien auch keine Aufspaltung der Valenz-und Deformations-Banden. Eine Aufspaltung ist aber charakteristisch für die Penta-und Tetrafluorometallate. Auf Grund der Lage der Banden wird zusätzlich die oktaedrische Koordination in den Hydraziniumfluorometallaten bewiesen. Mit der schwachen Wasserstoffbindung sind die IR-Spektren der NH4+-Ionen in deren Verbindungen erklärbar.

Double sulphates of rare earths(III) with trimethylammonium: Part 1. Synthesis and thermal behaviour of (CH3)3NHLn(SO4)2·3H2O

Abstract The double sulphates of some Ln(III) rare earths with trimethylammonium were obtained as crystalline products by evaporation at room temperature of an aqueous mixture of Ln(III) sulphate and trimethylammonium sulphate and treatment, in some cases, of the concentrated mixture with ethanol. After identification by means of X-ray powder diffraction patterns, it was found that three groups of double sulphates with different crystal structures were obtained. The results of the investigations of two groups with general empirical formula (CH 3 ) 3 NHLn(SO 4 ) 2 ·3H 2 O are given. They were examined by means of TG, DTG and DTA analyses, from 20 to 700° C. It was found that there is a difference in the thermal decomposition of these structurally different groups, in particular, a difference in the thermal decomposition of their anhydrous double sulphates.

Zur Kenntnis der Ammonium-fluoromanganate(III)

Investigation of the system MnF3−NH4F−HF−H2O revealed considerable hydrolysis even in highly acidic media. NH4MnF4 with a tetragonal unit cell,a=7.752 (6),c=6.153 (12) Å andZ=4, was isolated together with the already known (NH4)2MnF5 and (NH4)3MnF6. No splittings of the valence modes were observed with hexa- and penta-fluoromanganates, although the deformation of the octahedra was evident. Splitting was characteristic of the tetrafluoro compound. The spectrum of ammonium ion indicated increasing hydrogenbonding in the sequence hexa-, penta-, tetra-fluoromanganate.

Tetramethylammonium-fluoroaluminate,-gallate und-indate

Four new compounds have been isolated from the systemMF3−(CH3)4NF−HF−H2O (M=Al, Ga, In) and investigated by thermal analysis and IR spectroscopy. Tetrahedral coordination of Al(III) in (CH3)4NAlF4 seems most probable. This compound, the first known greater thermal stability than other dehydrates. IR spectra of all the other compounds may be interpreted on the basis of a distorted octahedral coordination.

Untersuchungen der Fluoro-metallate(III), 1. Mitt.: Hydrazinium(1+ und2+)-fluoro-aluminate,-gallate und-indate

ZusammenfassungVier neue Hydraziniumfluorometallate des Galliums und zwei neue des Indiums sowie das schon bekannte Pentafluoroaluminat wurden erhalten. Bei deren Herstellung spielt die Konzentration des Hydrogenfluorids eine ausschlaggebende Rolle. Auf Grund IR-spektroskopischer Daten ist eine oktaedrische Koordination der Metall(III)-Ionen, in einigen Fällen unter Verknüpfung zu Ketten, am wahrscheinlichsten.AbstractFour new gallium and two new indium compouds are described besides the already known hydrazinium(2+)-pentafluoraluminate. The concentration of hydrogen fluoride is shown to be of primary importance in their preparation. On the basis of IR spectra octahedral coordination of Me(III) ions seems to be most probable, in few cases these octahedra are joined through corners in chains.

Synthesis and thermal decomposition of some rare earth(III) dimethylammonium sulphate crystallohydrates: Part 1. Results of investigations of (CH3)2NH2Ln(SO4)3 · H2O (where Ln is La-Gd)

Abstract The double sulphates of some rare earths(III) with dimethylammonium were obtained as crystalline products by evaporation at room temperature of an aqueous mixture of Ln(III) sulphate and dimethylammonium sulphate in molar ratio from 1:4 to 1:15, and treatment, in some cases, of the concentrated mixture with ethanol. The identification was carried out by means of X-ray powder diffraction patterns. It was found that they are isostructural. On the basis of the thermal decomposition and chemical analysis of the obtained double salts, their general empirical formula (CH 3 ) 2 NH 2 Ln(SO 4 ) 2 · H 2 O was established. It was found that rare earth(III) sulphates are obtained at 700 °C. The thermal decomposition takes place in two well-resolved stages. The decomposition of the anhydrous double salts is not a simple dissociation, but involves intermediate reactions.

Kinetics of the thermal decomposition of Pr2(SO4)3 to Pr2O2SO4

Abstract The thermal decomposition kinetics of Pr2(SO4)3 to Pr2O2SO4 have been studied by isothermal weight change determination. The reaction was found to obey a linear law up to α = 0.5; beyond α = 0.5 it could be described as a phase-boundary controlled process. A dependence of the activation energy upon the sample weight was observed. The changes in surface area and density which occur during the decomposition are also given.

Untersuchungen der Fluoro-metallate(III), 2. Mitt.: Thermoanalytische Untersuchungen von Hydrazinium-(1+ und2+)-fluoro-aluminaten-gallaten, und-indaten

ZusammenfassungDie thermische Zersetzung dieser Verbindungen im Argon wird beschrieben und führt zu den drei neuen Verbindungen N2H5GaF4, N2H5InF4 und N2H5GaF4·N2H6F2. Außerdem sind zwei neue Phasen mit den Verhältnissen N2H4∶2 Ga∶6 F und N2H4∶In∶3F isolierbar. Die thermische Zersetzung von N2H6AlF5 verläuft analog dem N2H6GaF5 ohne trennbare Stufen. Gitterabstände und IR-Spektren der neuisolierten Phasen sind angegeben.AbstractThe thermal decomposition of these compounds in argon results in the following three new compounds: N2H5GaF4, N2H5InF4, and N2H5GaF4·N2H6F2. Besides, two new phases with composition N2H4∶2 Ga∶6 F and N2H4∶In∶3 F are noticed. The thermal decomposition of N2H6AlF5 follows the same path as N2H6GaF5, but no separable steps could be observed. IR spectra together with the d spacings of the new compounds are included.