Synthesis, characterization and the thermal decomposition of potassium tris(oxalato)lanthanum(III)nonahydrate
TL;DR: In this article, a tentative mechanism for the decomposition in air is proposed and the kinetic parameters, mainly E * of the dehydration and decomposition steps in TG, were calculated using four non-mechanistic equations.
About: This article is published in Thermochimica Acta.The article was published on 1999-10-25. It has received 10 citations till now. The article focuses on the topics: Thermal decomposition & Lanthanum.
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TL;DR: In this article, a tentative mechanism for the thermal decomposition in air of Lanthanum(III tris-tartrato lanthanate(III) decahydrate, La[La(C4H4O6)3]·10H2O was proposed.
Abstract: 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.
18 citations
TL;DR: In this paper, the TG/DSC curves of K 3 [Cr(C 2 O 4 ) 3 ]·3H 2 O, K 3[Al[C 2 OD 4 ]· 3H 2 OD, K 2 [Cu[C O 4 ] 2 ]·2H 2 2 O in nitrogen were determined at the heating rate of 15, 10, 5, and 2 ǫ cmin −1, respectively.
18 citations
TL;DR: In this article, the authors performed the characterisation of rare earth elements carbonates (REECs) by thermal analysis (TG-DTG) combined with simultaneous infrared evolved gas analysis-Fourier transform infrared (EGA-FTIR) spectroscopy.
17 citations
TL;DR: In this paper, the properties of chromium and lanthanum complexes were investigated using elemental analysis, IR, reflectance and powder X-ray diffraction (XRD) studies.
Abstract: The complexes M[La(C2O4)3]⋅xH2O (x=10 for M=Cr(III) and x=7 forM=Co(III)) have been synthesized and their thermal stability was investigated. The complexes were characterized by elemental analysis, IR, reflectance and powder X-ray diffraction (XRD) studies. Thermal investigations using TG, DTG and DTA techniques in air of chromium(III)tris(oxalato)lanthanum(III)decahydrate, Cr[La(C2O4)3]⋅10H2O showed the complex decomposition pattern in air. The compound released all the ten molecules of water within ∼170C, followed by decomposition to a mixture of oxides and carbides of chromium and lanthanum, i.e. CrO2, Cr2O3, Cr3O4, Cr3C2, La2O3, La2C3, LaCO, LaCrOx (2
17 citations
TL;DR: In this paper, the precursors were characterized by elemental analysis, IR, electronic spectral and powder X-ray diffraction studies and good crystalline nature with monoclinic structures predominates in manganese and NiOLa whereas triclinic structure was found in CoOLa and CuOLa.
Abstract: Heterobimetallic oxalato complex precursors, manganese(II)tetraaquatris(oxalato)lanthanate(III)hexahydrate (MnOLa), cobalt(II)pentaaquatris(oxalato)lanthanate(III)trihydrate (CoOLa), nickel(II)pentaaquatris(oxalato)lanthanate(III)hexahydrate (NiOLa) and copper(II)diaaquatris(oxalato)lanthanate(III)monohydrate (CuOLa) of the type, M3[La(C2O4)3(H2O)
m
]2·nH2O have been synthesized in aqueous medium. The precursors were characterized by elemental analysis, IR, electronic spectral and powder X-ray diffraction studies. The good crystalline nature with monoclinic structures predominates in MnOLa and NiOLa whereas triclinic structures were found in CoOLa and CuOLa. The solid-state thermal behaviour of the precursors was explored using TG, DTG and DTA in air. The MnOLa generated a mixture species consisting mainly of MnO2, Mn3O4, Mn5O8, La2O3 and LaMn7O12 at 1000 °C through the formation of several intermediate species at 380 and 570 °C. The studies revealed that CoOLa led mainly to LaCoO3 and La2CoO4 along with some oxides of both the cobalt and lanthanum at 1000 °C. In case of nickel analogue the mixture species identified at 1000 °C are mainly of La2NiO4, La2O3, Ni2O3 and NiO2. In case of CuOLa the product at 1000 °C consisted of La2CuO4, La2Cu2O5 and oxides of copper and lanthanum. The nature of decomposition of the precursors in nitrogen were seen from DSC study and the kinetic parameters i.e., E
*
, lnk
0, ΔH
#
, ΔS
#
and order of reaction of all the steps were evaluated and discussed.
16 citations
Cites background from "Synthesis, characterization and the..."
...350 cm -1 for the oxides and at 1350–1540, 1025, 845 and 715 cm -1 for CO3 2- of the oxy and dioxycarbonate [ 21 ] further authenticated their presence....
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...The IR bands of the species at 1360–1540, 1020, 840 and 670 cm -1 justified about the carbonate group [ 21 , 23] and at 615, 490, 400 and 330 cm -1 [24, 34, 35] gave credence...
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...It was considered worth while to explore the thermal behaviour of carboxylate compounds and therefore studied the complex precursors M[M(C2O4)3]xH2O(where x = 4f or M= Cr(III), x = 2 for M = Sb(III) and x = 9f or M= La(III)) [19], alkali metal-lanthanide–oxalate system of the types M3 [La (C2O4)3]xH2 O( M 1 = Li, Na and K) [20, 21 ]a s well as a...
[...]
...The display of subsequent inclined slope between 282 and 337 C (observed mass loss, 26%) gives the credence [20, 21 , 23] of the release of 3NiC2O4 and La2(C2O4)2.5 (calcd....
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References
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Book•
01 Jan 1978
TL;DR: This encyclopedic work includes authoritative coverage of atomic and molecular structure, organic chemistry (revised), inorganic, analytical, and electro- chemistry, mathematics as applied to chemistry, and more.
Abstract: Lange's Handbook has served as a leading source of reliable chemical information and data for chemists, engineers, and other technical specialists since l934. This encyclopedic work includes authoritative coverage of atomic and molecular structure, organic chemistry (revised), inorganic, analytical, and electro- chemistry, mathematics as applied to chemistry, and more. It also includes nomenclature consistent with recommendations of the IUPAC Commission rules.
7,848 citations
Additional excerpts
...The K2CO3 melts [32] at 9108C....
[...]
TL;DR: In this article, a thermocouple is used to measure the sample temperature in a Stanton HT-D thermobalance, the bead of which is positioned in or near the sample, depending on crucible design.
Abstract: THE use of thermogravimetric data to evaluate kinetic parameters of solid-state reactions involving weight loss (or gain) has been investigated by a number of workers1–4. Freeman and Carroll2 have stated some of the advantages of this method over conventional isothermal studies. To these reasons may be added the advantage of using one single sample for investigation. However, the importance of procedural details, such as crucible geometry, heating rate, pre-history of sample, and particle size, on the parameters has yet to be fully investigated. It is also necessary to ensure accurate temperature measurement, both for precision and also to detect any departure from a linear heating rate due to endo- or exo-thermic reactions. (The effect of these may be largely eliminated by the use of small samples.) In our present work (using a Stanton HT–D thermobalance) the sample temperature is measured directly by means of a thermocouple the bead of which is positioned in or near the sample, depending on crucible design, the wires of which run down a twin-bore rise rod. The connexion between the end of the thermocouple wires on the balance arm and the terminal block is made by 0.001 in. platinum and platinum/rhodium wires5. It has been shown that these wires do not affect the performance of the balance but act merely as a subsidiary damping. From the terminal block compensated cable leads to the cold junction and a potentiometric arrangement for direct measurement of the thermocouple output.
5,770 citations
Book•
01 Jan 1963
5,387 citations
"Synthesis, characterization and the..." refers methods in this paper
...The water vapour, carbon monoxide and carbon dioxide evolved during decomposition were identi®ed by IR spectroscopy [33]....
[...]
TL;DR: The No. 10123 1quart "Success" can as discussed by the authors dispenses solvent by finger pressure on the valve, which then closes upon release of the pressure, as indicated in the accompanying figure.
Abstract: use and allows it to dispense no more solvent than is needed when the swab-stick is dipped into it like a pen into an inkwell. Available in 4 oz., 6 oz., and 8 oz. sizes, the price ranges from $3. 50 to $3. 75. This same company also advertises a model No. 10123 1quart "Success" can which dispenses solvent by finger pressure on the valve, which then closes upon release of the pressure, as indicated in the accompanying figure. There is also a plunger can of I-pint size that dispenses solvent by pressure on the plunger. Price for the first type of can is about $8, for the second, about $7.
1,518 citations