Search Results

You are looking at 11 - 15 of 15 items for

  • Author or Editor: K. Szécsényi x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

Compounds obtained by a solid–gas phase reactions between copper(II) chloride and bromide and 2,4-, 2,6- 3,4- and 3,5-lutidines were studied using thermogravimetry, far-infrared, electronic spectroscopy and X-ray diffraction. The results were compared with the corresponding data for the similar compounds with methylpyridines and 2,4,6-collidine. A special attention was paid to the host-guest phenomenon, a new structural feature of transition-metal halide complexes.

Restricted access

Abstract  

We report the synthesis and the characterization (elemental analysis, FT-IR spectroscopy, thermal methods and molar conductivity measurements) of the mixed complexes of zinc with acetate and 3-amino-5-methylpyrazole, HL 1, [Zn(OAc)2(HL1)2], or 3-amino-5-phenylpyrazole, HL 2 [Zn(OAc)2(HL2)2], or 4-acetyl-3-amino-5-methylpyrazole, HL 3, [Zn(OAc)(L3)(HL3)]2, with isothiocyanate and HL 2 [Zn(SCN)2(HL2)2], or HL 3 [Zn(SCN)2(HL3)2], and with nitrate, isothiocyanate and 3,5-dimethyl-1-carboxamidinepyrazole, HL 4 [Zn(NO3)(NCS)(HL4)2]. The thermal decomposition of the complexes is generally continuous resulting zinc oxide as end product,except [Zn(OAc)(L3)(HL3)]2 in which case a well-defined intermediate was observed between 570–620 K. On the basis of the IR spectra and elemental analysis data of the intermediate a decomposition scheme is proposed.

Restricted access

Abstract  

Triammonium-N-dithiocarboxyiminodiacetate, (NH4)3L, a new dithiocarbamato derivative of iminodiacetate, has been synthesized. The coordination properties of the ligand were tested in reactions with copper(II), nickel(II) and palladium(II) salts in acidic solutions. Complexes with a general formula M(H2L)2 were obtained, with the coordination taking place through the sulfur atoms of the dithiocarbamate moiety. The new compounds were characterized by elemental analysis, UV/VIS and IR spectroscopy, thermal analysis and magnetic measurements. In addition, the ligand was characterized by 1H- and 13C-NMR spectroscopy and molar conductivity measurements. The copper(II) complex is paramagnetic, while the nickel(II) and palladium(II) compounds are diamagnetic. The thermal decomposition of all compounds is continuous and the thermal stability of the complexes is higher than that of the ligand, as expected.

Restricted access

Abstract  

The synthesis of copper(II) chloride complexes with 3,5-dimethylpyrazole, 1-carboxamidine-3,5-dimethylpyrazole, 5-amino-4-carboxamide-1-phenylpyrazole and 4-acetyl-3-amino-5-methylpyrazole is described. The compounds are characterized by elemental analysis, FT-IR spectroscopy, thermal methods, magnetic moment and molar conductivity measurements. Thermal decomposition of the dichloro-(3,5-dimethylpyrazole)-copper(II) complex results in an unstable intermediate with a stochiometric composition. The decomposition of the other compounds is continuous.

Restricted access

Metal complexes with girard reagents-based ligands

Part II. Copper(II) and zinc(II) complexes with pyridoxilidene and salicylidene Girard-T hydrazone

Journal of Thermal Analysis and Calorimetry
Authors: V. M. Leovac, K Mészáros Szécsényi, Lj. S. Vojinović Ješić, V. I. ćešljević, S. Markov, and T. Wadsten

Abstract  

Complex formation reactions of copper(II) and zinc(II) halides with pyridoxilidene Girard-T hydrazone dihydrate [H3PLGT]Cl2·2H2O and salicylidene Girard-T hydrazone [H2SalGT]Cl ligands are described. The composition of the complexes, determined by customary methods, can be presented by the formulas Cu(HPLGT)X2 (X=Cl and Br ), Zn(HPLGT)Cl2, Cu(HSalGT)Cl2·H2O and Zn(SalGT)Cl·2H2O. The structures of the compounds were compared by powder X-ray diffraction. Thermal stability of the compounds has been examined by TG and DSC. The ligands and the complexes were tested against some gram-positive and gram-negative bacteria and yeast.

Restricted access