Pyrolytic decomposition of some even chain length copper (II) carboxylates

Akanni, M. S.; Ajayi, Oluwatosin; Lambi, John Ngolui

doi:10.1007/bf01913894

Cited by 13 publications

(12 citation statements)

References 32 publications

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“…No alkene was found, unlike for the decomposition of even chain Cu/Hg carboxylate [24,25], suggesting that the chain length may also play a role in the decomposition pathway or that the decomposition mechanism is a result of the general catalytic activity of copper, resulting in the oxidation of ethylene to acetaldehyde [59].…”

Section: Discussionmentioning

confidence: 99%

Thermal decomposition of CuProp2: In-situ analysis of film and powder pyrolysis

Rasi

Silveri

Ricart

et al. 2019

Journal of Analytical and Applied Pyrolysis

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The thermal decomposition of CuProp2 in the form of film and powder was studied in different atmospheres by means of thermal analysis techniques (TG-MS, TG-IR, EGA), chemical-structural methods (FTIR, XRD, EA) and computational thermochemistry (VASP/PBE). The decomposition mechanism in terms of volatiles evolved was disclosed with the aid of ab-initio modeling; it was found to be dependent on the gas diffusion in and out of the sample and accelerated by a humid atmosphere. In films, the copper redox behavior showed sensitivity to the residual atmosphere. Finally, the role of the metal center is discussed in the frame of a general decomposition mechanism for metal propionates. Volatile species evolved during decomposition can be detected by means of thermogravimetry (TG) coupled with Evolved Gas Analysis (EGA), which mainly works by infrared (EGA-FTIR or TG-FTIR) or by mass spectrometry (EGA-MS or TG-MS) detection. In fact, by EGA-FTIR and EGA-MS, it was shown that the decomposition of propionates in inert atmospheres involves formation of radicals C2H5• and C2H5CO• (along with CO2) and their recombination to form a symmetrical ketone [20-22]. For longer chain salts such as Ca(II)decanoate, techniques like pyrolysis coupled to gas chromatography (GC) revealed a more complicated scenario where normal alkanes were found along with several symmetrical ketones [23]. For odd chain length of Cu(II)carboxylates like Cu(II)propionate, only MS has been used for the in-situ EGA analysis and 2-pentanone (asymmetrical ketone) was reported to be the main decomposition product [11]. Formation of this asymmetrical ke-tone implies cleavage of a CeC(C]O) bond, instead of the expected CeC(]O) and C(]O)eO bonds. Conversely, no ketones at all were observed for even chain carboxylates of copper(II) [24], mercury(II) [25] and silver(I) [26]. In fact, references [24,25] report on the

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Section: Discussionmentioning

confidence: 99%

Thermal decomposition of CuProp2: In-situ analysis of film and powder pyrolysis

Rasi

Silveri

Ricart

et al. 2019

Journal of Analytical and Applied Pyrolysis

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“…Though the thermal degradation of copper(II) carboxylates is to this day largely under investigated. Studies by Van My and coworkers [174] showed that the thermal degradation of short chain copper(II) carboxylates produced metallic copper under inert atmosphere whilst the oxide was produced in air [39,40] along with the parent alkanoic acid and or the a-olefin in some cases [175]. However, no comprehensive mechanism or kinetic models were proposed for their degradation behaviors.…”

Section: Divalent Carboxylatesmentioning

confidence: 99%

Theories and experimental investigations of the structural and thermotropic mesomorphic phase behaviors of metal carboxylates

Nelson

Taylor

2014

Appl Petrochem Res

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Investigations on the phase behaviors and structural properties of mono-, di-and poly-valent metal carboxylates are reviewed with reference to developments in experimental and theoretical concepts surrounding their liquid crystalline properties. The main methods of structural investigation such as X-ray diffraction, infrared and 13 C-NMR spectroscopies are examined in detail on the basis of common synthetic routes leading to the isolation of pure compounds. A detailed review of the thermal behaviors of several metal carboxylates is presented along with proposed theories and molecular models for odd-even alternation, chain length effects, phase structures and mesophase formation. Theories explaining the effects of metal ion radii and chain unsaturation are also discussed. Proposed degradation mechanisms resulting in the formation of various products and kinetic studies are also considered. Though this review highlights a number of investigations on the structural and phase properties of the mostly widely studied carboxylates, the results presented here strongly indicate that there is room for further studies on some of these systems.

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“…Consequently, the TG curves of 3 and 4 appear to exhibit four steps whereas 2 shows five steps of thermal degradation at a glance. Magnitude of final residue from all the three complexes is higher than that calculated for one mole of metal [28,[29][30][31] probably due to carbonaceous matter alongwith reduced metal. Further, it is worth to be mentioned that rerecorded TG curve of the heterobimetallic complex 4 on simultaneous TGA/DTA-MS device is superimposable on its original TG curve (Fig.…”

Section: Thermal Behaviour Of 2 Under Helium Atmospherementioning

confidence: 97%

Solid-state thermal degradation behaviour of 1-D coordination polymers of Ni(II) and Cu(II) bridged by conjugated ligand

Прасад

Kushwaha

Kumar

et al. 2013

J Therm Anal Calorim

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Monometallic complexes [CudadbyH 2 O] n (2) and [NidadbyH 2 O] n (3) and heterobimetallic complex [Cu 0.5 Ni 0.5 dadb.yH 2 O] n (4) {where dadbH 2 = 2,5-Diamino-3,6-dichloro-1,4-benzoquinone (1); y = 2-4; n = degree of polymerization} were characterized by elemental analysis, atomic absorption spectroscopy (AAS), infrared spectroscopy (FTIR), powder X-ray diffraction (XRD). The thermal behavior of the complexes was studied by thermal analysis (TG/DTA) under air as well as under helium atmospheres. The released gaseous products were investigated by evolved gas analysis (EGA), performed by an online coupled mass spectrometer (TG/DTA-MS). Thermal degradation of 2 under helium atmosphere is distributed over five steps whereas 3 and 4 exhibited only four degradation steps due to overlap of 2 nd and 3 rd degradation steps of into one major step. All the complexes exhibit three steps degradation under air. The complex 2 loses NH group in second and HCl/Cl 2 , CO groups simultaneously in third steps of decomposition under helium whereas it loses NH and CO groups simultaneously in low temperature region of second step of degradation under air atmosphere as the loss of CO group is facilitated by air. EGA-MS under air and helium atmospheres shows that HCl, CO/CO 2 and (CN) 2 fragments are lost simultaneously at multiple steps, and not successively as predicted earlier. Rate of evolution of most evolved gases exhibits several maxima as a consequence of degradation followed by recombination reactions. Final residues under air and helium atmospheres correspond to the metal oxides and metals along with some carbonaceous matter, respectively.

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Pyrolytic decomposition of some even chain length copper (II) carboxylates

Cited by 13 publications

References 32 publications

Thermal decomposition of CuProp2: In-situ analysis of film and powder pyrolysis

Thermal decomposition of CuProp2: In-situ analysis of film and powder pyrolysis

Theories and experimental investigations of the structural and thermotropic mesomorphic phase behaviors of metal carboxylates

Solid-state thermal degradation behaviour of 1-D coordination polymers of Ni(II) and Cu(II) bridged by conjugated ligand

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