Search Results

You are looking at 1 - 10 of 246 items for :

  • "palladium" x
  • All content x
Clear All
Journal of Thermal Analysis and Calorimetry
Authors: J. Botelho, A. Souza, L. Nunes, A. Chagas, I. Garcia dos Santos, M. da Conceição, and P. Dunstan

Abstract  

The standard molar enthalpies of formation of crystalline dialkyldithiocarbamates chelates, [Pd(S2CNR2)2], with R=C2H5, n-C3H7, n-C4H9 and i-C4H9, were determined through reaction-solution calorimetry in acetone, at 298.15 K. From the standard molar enthalpies of formation of the gaseous chelates, the homolytic (172.43.8, 182.53.2,150.93.1 and 162.63.1 kJ mol−1) and heterolytic (745.03.8, 803.73.3,834.33.1 and 735.23.0 kJ mol−1) mean palladium-sulphur bond-dissociation enthalpies were calculated.

Restricted access

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.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: J. Regis Botelho, A. Duarte Gondim, I. Garcia dos Santos, P. Dunstan, A. Souza, V. Fernandes, and A. Araújo

Abstract  

The standard molar enthalpy of formation of crystalline dialkyldithiocarbamate chelates, [Pd(S2CNR2)2], with R=CH3 and i-C3H7, was determined through reaction-solution calorimetry in 1,2-dichloroethane, at 298 K. Using the standard molar enthalpies of formation of the gaseous chelates, the homolytic (52618 and 66610) and heterolytic (269318 and 295710 kJ mol-1) mean enthalpies of palladium-sulphur bond dissociation were calculated.

Restricted access
Journal of Flow Chemistry
Authors: Masaharu Ueno, Yasuharu Morii, Kiyoko Uramoto, Hidekazu Oyamada, Yuichiro Mori, and Shū Kobayashi

Continuous-flow hydrogenation of aromatic nitro compounds was successfully performed by using polysilane-supported palladium catalysts to afford the corresponding amino compounds in high yields. Productivity was high, and a wide variety of nitro compounds were applicable under the continuous-flow conditions. It is noted that no leaching of palladium was observed by inductively coupled plasma analysis.

Restricted access

Introduction Palladium supported carbon materials (activated carbon, carbon fibres, carbon black, nanotubes) are highly suitable catalysts for several chemical and electrochemical reactions [ 1 – 13 ]. Relevant concerns

Open access

New palladium(II) complexes with pyrazole ligands

Part I. Synthesis, spectral and thermal studies, and antitumor evaluation

Journal of Thermal Analysis and Calorimetry
Authors: Carolina V. Barra, Fillipe V. Rocha, Adelino V. G. Netto, B. Shimura, Regina C. G. Frem, Antonio E. Mauro, Iracilda Z. Carlos, Sandra R. Ananias, and Marcela B. Quilles

νNN band to higher frequencies (Δν ≅ 60–125 cm −1 ) compared to that of the free ligands indicates a strengthening of the N–N bond as a result of the interaction between palladium(II) and pyridine-like nitrogen atom [ 31 ]. The ν as SCN vibration for

Restricted access

New palladium(II) complexes with pyrazole ligands

Part II. Synthesis, spectral and thermal studies, and antitumor evaluation

Journal of Thermal Analysis and Calorimetry
Authors: Carolina V. Barra, Fillipe V. Rocha, Adelino V. G. Netto, Regina C. G. Frem, Antonio E. Mauro, Iracilda Z. Carlos, Sandra R. Ananias, and Marcela B. Quilles

the most active derivative (a palladium complex) being about 16 times more active than cisplatin against the cisplatinum-resistant cell line A2780cisR [ 6 ]. Thermal studies on this class of complexes have also attracted considerable attention

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: N. Ivashchenko, V. Tertykh, V. Yanishpolskii, J. Skubiszewska-Zięba, R. Leboda, and S. Khainakov

silver, gold, and palladium nanoparticles on the surface of such hydride silicas was studied [ 7 , 12 – 15 ]. Direct reduction of ions on the hydride silica surface allowed us to control the sizes of formed metal particles within certain limits by

Restricted access

oxidation of methane at low temperature have been extensively studied so far [ 9 – 14 ]. In particular, palladium-based systems have been widely reported in literature as the catalyst of choice in methane combustion [ 15 , 16 ]. Some properties of these

Restricted access