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Abstract  

The complexes of piperidine dithiocarbamate, 2-aminopyridine dithiocarbamate and organotin(IV) of the type R3Sn(L1), R2Sn(L1)2, R3Sn(L2), R2Sn(L2)2, [R=C6H5CH2 (benzyl), p-ClC6H4CH2 (p-chlorobenzyl), L 1=sodium piperidine dithiocarbamate and L 2=sodium 2-aminopyridine dithiocarbamate] have been synthesised and characterised by spectral studies (IR, UV, 1H NMR). Thermogravimetric (TG) and differential thermal analytical (DTA) studies have beeen carried out for these complexes and from the TG curves, the order and apparent activation energy for the thermal decomposition reactions have been elucidated. The various thermal studies have been correlated with some structural aspects of the complexes concerned. From DTA curves, the heat of reaction has been calculated.

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Some new organotin(IV) complexes with kojic acid and maltol

Synthesis, characterization and thermal studies

Journal of Thermal Analysis and Calorimetry
Authors: Reena Jain and N. Kaushik

Abstract  

Organotin(IV) complexes of kojic acid and maltol of the type R3Sn(L) and R2Sn(L)Cl [R=C6H5CH2-,p-ClC6H4CH2-; HL=kojic acid, maltol] have been synthesized in anhydrous THF. They were characterized by UV, IR,1H NMR, and mass spectral studies. Their activityvs. E. coli, S. aureus and P. pyocyanea bacterial strains have been studied and the general order of activity is S. auresu>P. pyocyanea>E. coli. In all the complexes, the ligand acts as bidentate, forming a five membered chelate ring. All the complexes are 1∶1 metal ligand complexes. Various thermodynamic parameters have been calculated for the first two decomposition steps using TG/DTA/DSC curves. (p-ClC6H4CH2)3Sn(L) complexes have the minimum and (C6H5CH2)2Sn(L)Cl complexes have the maximum activation energy.

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The thermal decomposition in the solid-phase has been studied by thermogravimetric (TG) and differential thermal analysis (DTA) techniques for a number of heterocyclic thiol complexes. The method of Coats and Redfern was used to study the kinetics of the thermal decomposition process. The enthalpy changes and activation energies for the decomposition have been calculated.

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Abstract  

Ionic chelate complexes of kojic acid(I) and hafnium(IV) of the type [(η5-C5H5)2HfL]+[MCl3] (II)[HL=kojic acid; M=Zn(II), Cd(II), Hg(II), Cu(II)] have been synthesised and characterised by spectral studies (IR, UV, 1H NMR and 13CNMR). Thermogravimetric (TG) and differential thermal analytical (DTA) studies have been carried out for these complexes and from the TG curves, the order and apparent activation energy for the thermal decomposition reactions have been elucidated. The various thermal studies have been correlated with some structural aspects of the complexes concerned. From DTA curves, the heat of reaction has been calculated.

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Abstract  

A number of ionic chelate complexes of maltol(A) and hafnium(IV) the type[(η5−C5H5)2HfL]+[MCl3] (B) [HL=maltol; M=Zn(II), Cd(II), Hg(II), Cu(II)]have been synthesized and characterized by spectral studies (IR, UV, 1H NMR and 13C NMR). The stoichiometry of the complexes has been confirmed by conductance measurements. Thermogravimetric (TG) and differential thermal analytical (DTA) studies have been carried out for these complexes and from TG curves, the order, apparent activation energy and apparent activation entropy of the thermal decomposition reactions have been elucidated .The order in each case has been determined to be one and the degree of spontaneity and lability have been inferred from the apparent activation energy and entropy, respectively. Thermal parameters have been correlated with some structural aspects of the complexes concerned. From differential thermal analysis curves, the heat of reaction has been calculated.

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Abstract  

Palladium(II) complexes of type [Pd(L)Cl2] [where L=2-aminopyridine-N-thiohydrazide (L1), (2-aminopyridine-N-thio)-1,3-propanediamine (L2), benzaldehyde 2-aminopyridine-N-thiohydrazone (L3) and salicylaldehyde-2-aminopyridine-N-thiohydrazone (L4)] have been synthesized. The thiohydrazide, thiodiamine and thiohydrazones can exist as thione-thiol tautomer and coordinate as a bidentate N-S ligand. The ligands found to act in bidentate fashion. The complexes have been characterized by elemental analysis, IR, mass, electronic, 1H NMR spectroscopic studies, and TG/DTA study. Antifungal studies of some complexes were also carried out. Various kinetic and thermodynamic parameters like order of reaction (n), activation energy (E a), apparent activation entropy (S #) and heat of reaction (ΔH) have also been carried out for one complex.

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