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Abstract  

Thermal behaviour of a few lanthanide complexes of the type ML3(I) [M=Eu,Gd; HL=4,4,4-trifluoro- 1-(2-napthyl)-1,3-butanedione and EuL30.5dmm dmm=2,6-dimethylmorpholine(II)], has been investigated. From thermogravimetric(TG) curves, the decomposition pattern of the compounds has been analysed on the basis of mass loss data. The order and activation energy of the thermal decomposition reactions have been elucidated. From differential thermal analysis (DTA) studies, the heat of reaction and rate of thermal decomposition reaction have been enumerated.

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Abstract  

The two complexes of [Ln(CA)3bipy]2 (Ln = Tb and Dy; CA = cinnamate; bipy = 2,2′-bipyridine) were prepared and characterized by elemental analysis, infrared spectra, ultraviolet spectra, thermogravimetry and differential thermogravimetry techniques. The thermal decomposition behaviors of the two complexes under a static air atmosphere can be discussed by thermogravimetry and differential thermogravimetry and infrared spectra techniques. The non-isothermal kinetics was investigated by using a double equal-double steps method, the nonlinear integral isoconversional method and the Starink method. The mechanism functions of the first decomposition step of the two complexes were determined. The thermodynamic parameters (ΔH , ΔG and ΔS ) and kinetic parameters (activation energy E and the pre-exponential factor A) of the two complexes were also calculated.

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number of transition and lanthanide complexes with series of the pyridinedicarboxylic acids, which includes the 2,3-, 2,4-, 2,5-, 2,6-, 3,4-, and 3,5-pyridinedicarboxylic isomers, have been reported in the recent two decades. Although there are many

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The electrical conductivities and the electronic, IR and NMR spectra were measured for some ethyl cyanoacetate phenylhydrazone derivatives and their lanthanide complexes in the temperature range 20–200‡C. Semiconducting behaviour was detected for these systems (positive dσ/dT). A correlation was established between the electrical properties and the structures of the free ligand molecules and their complexes. The mechanism of the conduction process was evaluated. The electronic absorption spectra in ethanol were measured and are discussed. Elemental analyses were performed and the IR and NMR spectra (of the diamagnetic complexes) were measured to throw more light on the structures of these complexes.

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Abstract  

Ethylenediaminotetramethylenephosphonic acid (EDTMP, H8L) was prepared and its complexes with some lanthanide ions (La, Eu, Gd and Sm) were isolated under various conditions. IR spectra and thermal stabilities of EDTMP and its complexes were studied. The experimental conditions of the preparation influence to the composition of the complexes were shown. In alkaline solution (pH=8) deprotonated (P(O)(O)2), and in acidic solution (pH=3–4) deprotonated and partly protonated (P(O)(O)(OH)) and non-protonated (P(O)(OH)2) phosphonic groups are present in the complexes. All the complexes contain coordinated water molecules. The complexes containing a protonated phosphonic group contain coordinated and hydrogen-bonded water molecules.

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Lanthanide complexes of 3-methoxy-salicylaldehyde

Thermal and kinetic investigation by simultaneous TG/DTG–DTA coupled with MS

Journal of Thermal Analysis and Calorimetry
Authors: Christos Papadopoulos, Nikolaos Kantiranis, Stefano Vecchio, and Maria Lalia-Kantouri

Abstract  

The reaction of a lanthanide(III) nitrate (Ln = Pr, Nd, Gd, Dy, Er) with 3-methoxy-salicylaldehyde(3-OCH3-saloH), afforded neutral complexes of the general formula [Ln(3-OCH3-salo)3], which were characterized by means of elemental analysis, FT-IR spectra, TG-DTA curves, and magnetic measurements. The released products, due to the thermal decomposition were analyzed by on-line coupling MS spectrometer to the thermobalance in argon, allowed to prove the proposed decomposition stages. In order to confirm the stability scale provided on the basis of the onset decomposition temperature, a kinetic analysis of the three decomposition stages was made using the Kissinger equation, while the complex nature of the decomposition kinetics was revealed by the isoconvertional Ozawa–Flynn–Wall method.

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[ 21 ]. Imai et al . [ 22 ] synthesized and characterized [Ln(CCl 2 HCOO) 3 (H 2 O) 5 ] n (where Ln(III) = La, Pr, Nd, Eu) and their properties were measured. There are scant information about lanthanide complexes with bipyridine isomers and

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. Monga , V , Patrick , BO . 2005 . Orvig Ch. Group 13 and lanthanide complexes with mixed O, S anionic ligands derived from maltol . Inorg Chem . 44 : 2666 – 2677 10.1021/ic048693y . 48

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The multi-step dehydration and decomposition of trivalent lanthanum and lanthanide heptanediate polyhydrates were investigated by means of thermal analysis completed with infrared study. Further more, X-ray diffraction data for investigated heptanediate complexes of general stoichiometry Ln2(C7H10O4)3.nH2O (wheren=16 in the case of La, Ce, Pr, Nd and Sm pimelates,n=8 for Eu, Gd, Tb, Dy, Er and Tm pimelates,n=12 for Ho, Yb and Lu pimelates) were also reported.

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