The complexes of yttrium(III) and lanthanides(III) with 1,2,4,5-benzenetetracarboxylic acid were prepared as crystalline solids of the general formula Ln4(C10H2O8)3⋅14H2O. They are insoluble in ...water. On heating in air or inert gas atmosphere all compounds lose water molecules; next anhydrous compounds decompose to oxides. The yttrium complex and heavy lanthanide (from Ho to Lu) ones crystallize in monoclinic crystal system. The dehydration does not change the crystal structure of the compounds.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Rare earth elements 1,3,5-benzenetricarboxylates were prepared as solids of the general formula Ln(C9H3O6)*nH2O, where n=6 for La-Dy and n=4 for Ho-Lu,Y. Their solubilities in water at 293 K are of ...the order 10-10 mol dm. The IR spectra of the complexes indicate that the carboxylate groups are bridging and bidentate chelates. Hydrated 1,3,5-benzenetricarboxylates lose water molecules during heating in one step (La-Tb), two steps (Y, Ho-Tm) or three steps (Dy, Yb, Lu). The anhydrous complexes are stable up to 573-742 K and decompose to oxides (Ce-Lu) at higher temperatures.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The crystal structure of Na
2
ReCl
6
·6H
2
O is determined. The crystallographic characteristics are as follows:
a
= 6.6955(2) Å,
b
= 7.0926(2) Å,
c
= 8.3667(3) Å; α = 102.567(1)°, β = 98.853(2)°, γ ...= 107.236(1)°;
V
= 360.08(2) Å
3
,
P
-1 space group,
Z
= 1,
d
x
= 2.550 g/cm
3
. The thermal properties of Na
2
ReCl
6
·6H
2
O are studied in the hydrogen atmosphere. During the thermolysis of Na
2
ReCl
6
0.50
PtCl
6
0.50
·6H
2
O double complex salt in the hydrogen atmosphere, Re
x
Pt
1−
x
nanocrystalline solid solutions were obtained.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The complexes of yttrium(III) and lanthanides(III) with 5-amino-1,3-benzenedicarboxylic acid form two isostructural series of compounds and have the general formula Ln2(C8H5O4N)3·nH2O, where n = 13 ...for Y, La-Er and n=9 for Tm, Yb, Lu. They are insoluble in water and stable at room temperature. On heating in air or inert gas atmosphere they lose all water molecules in several steps. The anhydrous compounds are stable to about 400°C and next decompose to oxides.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
In the system of a homologous series of sodium alkyl sulfates, including SLS (sodium lauryl sulfate) and other anionic surfactants with various phenols and other materials as additives, the ...surfactant molecular complex formation was obviously proved from results of X-ray diffraction experiment on their powdery specimens and from the elementary analysis such as UV spectroscopy. Especially, well-grown single crystals occurring in a SOS (sodium octyl sulfate)/2-naphthol system provided detailed structural knowledge of the anionic surfactant molecular complex to establish the unambiguous existence of those complex species. In comparison with previous results of the cationic surfactant molecular complexes, significant variation observed in the X-ray diffractograms of the anionic complex species deduced almost no change or only slight contraction of the unit cell of the anionic mother surfactant crystals along their longest lattice direction, while in all cationic complexes a clear expansion was involved associated with the additive intrusion into the surfactant crystal lattices. The remarkable features on the diffractograms of the anionic complex species also corresponded well to observations in which many sorts of anionic complex species were hydrated and the additive stability occluded in their mother surfactant crystal structure was very poor compared with the cationic complex species.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The dissociation constances of (RS)-1-isopropyl dihydrogen citrate and the stability constants of its metal complexes with Cu(II), Ca(II) and Zn(II) have been determined in the aqueous state by a ...potentiometry. The solid-solid phase transition of its Zn(II) complex has been studied by the thermogravimetry/differential thermal analysis (TG/DTA), IR spectrometry and X-ray powder analysis. It was found that the physical properties, this is, the contents of the water molecule of crystallization, the coordination geometries and the crystal structures before and after the transition, were changed.
The X-ray diffraction patterns of two polymorphic forms of riboflavin tetrabutyrate (RTB) powders were examined. The orange powder showed sharp peaks suggesting a well-crystallized material, while ...the yellow powder showed broad peaks suggesting a polymer-like material. By using the cell constants of RTB crystal, all peaks in the Debye-Sheller powder patterns of RTB were assigned. Increase of the ratio of H2O in the recrystallization solvent (MeOH-H2O) decreased the peak intensities of X-ray patterns corresponding to specific faces of RTB crystals, reflecting the direction of growth of RTB crystals in the presence of H2O.
Crystal structures of the high temperature form (γII) of γII-Li2CoSiO4 and γII-Li2MgSiO4 and the low temperature form (βII) of βII-Li2ZnSiO4 have been determined from X-ray powder data on the basis ...of known structures, γII-Li2ZnSiO4 and βII-Li2CoSiO4. The three compounds of the γII form (space group P 21/n) are isostructural with each other. The two compounds of the βII form (space group Pbn 21), which are also isostructural with each other, show the same disorder as that found in a single crystal of βII-Li2CoSiO4. Both the γII and βII forms consist of subcells, P and Q, each having two units of Li2MSiO4 related by an n-glide; the symmetry elements connecting subcells P and Q characterize the formation of the two polymorphic forms. All cations are coordinated tetrahedrally by O atoms.
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