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  • Author or Editor: K. Györyová x
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Abstract  

New zinc acetate based complex compounds (of general formula Zn(CH3COO)2·1−2L·nH2O) containing one or two molecules of urea, thiourea, coffeine and phenazone were prepared namely: Zn(CH3COO)2·2.5H2O, Zn(CH3COO)2·2u·0.5H2O, Zn(CH3COO)2·tu·0.5H2O, Zn(CH3COO)2·2tu, Zn(CH3COO)2·cof·2.5H2O, Zn(CH3COO)2·2cof·3.5H2O, Zn(CH3COO)2·2phen·1.5H2O. The compounds were characterized by IR spectroscopy, chemical analysis and thermal analysis. Thermal analysis showed that no changes in crystallographic modifications of the compounds take place during (heating in nitrogen before) the thermal decompositions. The temperature interval of the stability of the prepared compounds were determined. It was found that the thermal decomposition of hydrated compounds starts by the release of water molecules. During the thermal decomposition of anhydrous compounds in nitrogen the release of organic ligands take place followed by the decomposition of the acetate anion. Zinc oxide and metallic zinc were found as final products of the thermal decomposition of the zinc acetate based complex compounds studied. Carbon dioxide and acetone were detected in the gaseous products of the decomposition of the compounds if ZnO is formed. Carbon monoxide and acetaldehyde were detected in the gaseous products of the decomposition, if metallic Zn is formed. It is supposed that ZnO and Zn resulting from Zn acetate complex compounds here studied, possess different degree of structural disorder. Annealing takes place by further heating above 600°C.

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It was found by DTA and TG that [Phenyl2I][Ag(CN)2] in the solid state is chemically stable on heating in argon up to 160°C. During heating to higher temperatures it decomposes, forming volatile products such as [Phenyl]I, [Phenyl]NC and (CN)2 [1]. After heating the sample to 500°C metallic silver resulted. The volatile and intermediate solid products were analysed by IR-spectroscopy.

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Abstract  

The new zinc ternary complexes [Zn(cyclen)NO3]ClO4 (I), [Zn2(cyclen)2(m-nic)](ClO4)3 (II), [Zn2(cyclen)2(m-pic)](ClO4)3 (III) (cyclen=1,4,7,10-tetraazacyclododecane; nic=nicotinic acid; pic=picolinic acid) were synthesized and their spectral and thermal properties were investigated. The compounds were characterized by elemental analysis, IR spectroscopy and TG/DTG, DTA methods. Moreover, the way of coordination of pyridinecarboxylate anions was proposed on the basis of the spectral data and consequently proved with results of X-ray structure analysis.

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Summary Three new complex compounds of general formula Zn[5-ClC6H3-2-(OH)COO]2·L2·nH2O (where L=thiourea (tu), nicotinamide (nam), caffeine (caf), n=2-5), were prepared and characterized by chemical analysis, IR spectroscopy and their thermal properties were studied by TG/DTG, DTA methods. It was found that the thermal decomposition of hydrated compounds starts with the release of water molecules. During the thermal decomposition of anhydrous compounds the release of organic ligands take place followed by the decomposition of salicylate anion. Zinc oxide was found as the final product of the thermal decomposition performed up to 800°C. RTG powder diffraction method, IR spectra and chemical analysis were used for the determination of products of the thermal decomposition.

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Abstract  

Results of a literature search on thermal analysis reference materials are listed

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The intermediates formed from Mo(NO)2Cl2 L 2 and Mo(NO)Cl3 L 2 by splitting-off of weakly-coordinated ligandsL (alcohols, glycols, nitriles) decompose in exothermic reactions: the decomposition products are N2, MoOCl4 and MoO3. If the ligandL is strongly coordinated and is reducing (DMFA, DMSO, Pph3, Asph3), the NO groups oxidize the ligandL by formation of N2 in an exothermic intramolecular redox process under 300‡. The central atom is oxidized by NO, and N2O is formed above 300‡ in the case of non-reducing ligandsL (OPph3, OAsph3). An endothermic redox reaction with chlorine formation is observed during decomposition of the trichloro complex. The solid residue is metallic molybdenum.

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Abstract  

New zinc complex compounds of general formula ZnL2,X2 {X=CI, Br; L=phenazone(phen), nicotinamide(nam)} were synthesized. The new compounds were characterized by elemental analysis, IR spectroscopy and DTA, TG/DTG methods. Thermal properties of the new compounds were investigated. It was found that nicotinamide, phenazone and ZnCl2 or ZnBr2 are released during the thermal decomposition of the compounds. Mass spectroscopy has been used for the determination of the thermal decomposition intermediate products.

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