Thermal decomposition behaviour of lanthanum(III) tris-tartrato lanthanate(III) decahydrate

Lanthanum(III) tris-tartrato lanthanate(III) decahydrate, La[La(C₄H₄O₆)₃]·10H₂O has been synthesized and characterized by elemental analysis, IR, electronic spectral and X-ray powder diffraction studies. Thermal studies (TG, DTG and DTA) in air showed a complex decomposition pattern with the generation of an anhydrous species at ~170°C. The end product was found to be mainly a mixture of La₂O₃ and carbides at ~970°C through the formation of several intermediates at different temperature. The residual product in DSC study in nitrogen at 670°C is assumed to be a similar mixture generated at 500°C in TG in air. Kinetic parameters, such as, E*, ΔH, ΔS, etc. obtained from DSC are discussed. IR and X-ray powder diffraction studies identified some of the decomposition products. The tentative mechanism for the thermal decomposition in air of the compound is proposed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Crystal structure of barium isothiocyanato(ethylenediaminetetraacetato)cobaltate(III)

All-Union Scientific-Research Institute for Chemical Reagents and Highly Pure Chemical Substances. M. V. Lomonosov Moscow State University. Translated from Zhurnal Strukturnoi Khimii, Vol. 29, No. 4, pp. 120–127, July–August, 1988.     

Anhydrous Neodymium(III) Acetate

Anhydrous neodymium(III) acetate, Nd(OAc)₃ was obtained as light purple single crystals by direct oxidation of neodymium metal with malonic acid in a glass ampoule at 180 °C. It crystallizes with the monoclinic space group P2₁/a (no. 14) with a = 2201.7(2), b = 1850.0(1), c = 2419.0(3) pm, β = 96.127(8)°, V = 9796.8(1)·10⁶·pm³, Z = 40 [Nd(OAc)₃], R₁ = 0.0430 [I₀ > 2σ(I₀)]. Most of the Nd³⁺ cations are coordinated by nine (or eight) oxygen atoms of acetate ligands which bridge these polyhedra to slightly waved layers which are stacked in the [010] direction.     

Solid-state thermal decomposition of heterobimetallic oxalate coordination compounds, zinc(II)tetraaquatris(oxalato)lanthanate(III)hexahydrate and cadmium(II)heptaaquatris(oxalato)lanthanate(III)tetrahydrate

Two heterobimetallic oxalate coordination compounds, zinc(II)tetraaquatris(oxalato)lanthanate(III)hexahydrate (ZnOLa) and cadmium(II)heptaaquatris(oxalato)lanthanate(III)tetrahydrate (CdOLa) were synthesized and characterized by elemental analysis, IR, electronic spectral and powder X-ray diffraction studies. Both the compounds were found to have monoclinic structure. Thermal decomposition studies by TG, DTG and DTA in air have proved that the aqua ligands are associated with metals in a stronger coordination mode. The temperatures for pyrolysis were adopted from the TG results chosen from the stable range of thermograms. In case of ZnOLa, it decomposes through two steps and the end product at 1000 °C was found to be consisting of mainly, La₂O_3, ZnO and La₂ZnO _x through the intermediate formation of several oxycarbonates of lanthanum at ca. 525 °C. In case of cadmium analogue, three steps decomposition were observed and the final products were confirmed as CdO₂, La₂O₃, LaCO and La₂CdO _x via the formation of several intermediates at 340 and 590 °C. The La₂C₃ and carbon are also found as part of the end product. The kinetic parameters, E ^*, lnk _o, ?H ^# and ?S ^# of all the deaquated and decomposition steps are investigated and discussed from the DSC study in nitrogen.     

Synthesis and Structure of Europium(III) o-Methylbenzoates

Russian Journal of General Chemistry - Heteroligand europium(III) complexes with o-methylbenzoic acid and neutral N- and P-organic compounds were obtained and characterized by chemical analysis,...     

Thermodynamics and mechanism of oxidation of aqua(ethylenediaminetetraacetato)chromium(III) in ethanolwater solvents

Summary The kinetics of the oxidation of aqua(ethylenediaminetetraacetato)chromium(III) by periodate have been investigated in various ethanol: water mixtures in the 0–54 wt% ethanol range, at six different temperatures in the 15–40°C range. The effect of solvent on the rate and mechanism of the reaction has been studied and an innersphere mechanism for the reaction is proposed, consistent with the calculated activation parameters.     

Sodium Salts of Anionic Chiral Cobalt(III) Complexes as Catalysts of the Enantioselective Povarov Reaction

The sodium salts of anionic chiral cobalt(III) complexes (CCC^?Na⁺) have been found to be efficient catalysts of the asymmetric Povarov reaction of easily accessible dienophiles, such as 2,3‐dihydrofuran, ethyl vinyl ether, and an N‐protected 2,3‐dihydropyrrole, with 2‐azadienes. Ring‐fused tetrahydroquinolines with up to three contiguous stereogenic centers were thus obtained in high yields, excellent diastereoselectivities (endo/exo up to >20:1), and high enantioselectivities (up to 95:5 e.r.).     

Solid Solutions of Europium(III) and Gadolinium(III) Trifluoroacetate Trihydrates as Precursors of Solid Solutions of Europium and Gadolinium Trifluorides

The system Eu(CF₃CO₂)₃-Gd(CF₃CO₂)₃-H₂O, which forms solid solutions Eu_xGd₁-x(CF₃CO₂)₃ · 3H₂O, was studied. The thermolysis of these solutions at 350-360°C yields solid solutions of lanthanide trifluorides. X-ray examination showed that these solid solutions are formed on the basis of the predominantly rhombic phase of Eu(III) and Gd(III) trifluorides.