Search Results

You are looking at 21 - 30 of 62 items for

  • Author or Editor: G. Liptay x
  • Refine by Access: All Content x
Clear All Modify Search

Heterogeneous reactions of solid nickel(II) complexes, XI

The influence of different experimental conditions on the stoichiometry of thermal decomposition of the complex Ni(NCS)2(β-picoline)4

Journal of Thermal Analysis and Calorimetry
Authors: T. Šramko, G. Liptay, and E. Jóna

The influence of factors caused by different experimental conditions on the stoichiometry of thermal decomposition of the complex Ni(NCS)2(β-picoline)4 was studied. By means of TG it was found that the release ofβ-picoline was shown by the derivatograph (air atmosphere, sample of 50–500 mg, rate of temperature increase 1–6°/min, crucible with a hole in the bottom) in three steps (−2, −1, −1), by the micro-balance (sample of 2.59 mg) in two steps (−2, −2), and by the vacuum thermobalance in one step (−4). Under quasi-isothermal and quasi isobaric conditions in a special crucibleβ-picoline was released in three steps (−1, −2, −1). An analogous result was obtained with the derivatograph using a crucible with a lid. The reasons for these differences are discussed.

Restricted access

The stepwise thermal decomposition of [Ni(py)4]Cl2 was studied by means of a derivatograph. The stepwise mode of thermal decomposition allowed the preparation of new complexes. X-ray powder diffraction and IR methods were used to study the structures of the decomposition intermediates. [Ni(py)4]Cl2 was applied as a model substance. The decompositions of a great number of complex compounds of similar type have been reported, but only a few of them have been investigated structurally by single-crystal X-ray diffraction techniques due to the difficulty of obtaining large single-crystals.

Restricted access

Abstract  

Parent and mixed-ligand cobalt(II) complexes of different compositions were prepared with water, sulfate ion and 1,2-ethanediol as ligands. The magnetic susceptibility data, the IR spectra and the thermoanalytical curves of the complexes were recorded. Oxygen atoms bound by one or two coordinate bonds to the metal ion, or by hydrogen-bonds were observed in the crystals pace.

Restricted access

Pyridin type complexes of transition-metalhalides

I. Preparation, characterization and thermal analysis studies of cobalt(II)-chlorides with 2,3,4-methylpyridines

Journal of Thermal Analysis and Calorimetry
Authors: G. Liptay, G. Kenessey, L. Bihátsi, T. Wadsten, and J. Mink

A large number of Co-picoline-chlorides were prepared from different reaction media by changing the Co: picoline molar ratio.

Restricted access

The preparation and some properties of complexes ofp-tolylacetic acid with cobalt, nickel and copper are described. Magnetic measurements, electronic and far infrared spectra show that the metal complexes have octahedral structures. Infrared spectra indicate that coordination takes place through the carboxyl group to the metal ions and that the water molecule in each of the complexes is present as water of crystallisation. Thermogravimetry studies also show that the water molecules in each of the complexes do not form a coordinate bond with the metal ion. Differential thermal analysis show that the dehydration processes are accompanied by endothermic reactions. In each case the anhydrous metal complex undergoes an exothermic reaction to give the metal oxide.

Restricted access

Abstract  

The chloro complexes of cobalt, nickel and copper with 3-phenylpyridine were prepared in ethanolic solution from which solid compounds were isolated. The cobalt and copper complexes have stoichiometry M2LCl4 while the nickel complex has stoichiometry NiLCl2. The suggested structure for the cobalt and copper complexes is tetrahedral, while for the nickel complex it is octahedral. Thermal analysis studies show that the cobalt and copper complexes form intermediate complexes before their metal oxides are produced. The nickel complex also forms an intermediate complex and then nickel chloride before the nickel oxide is obtained.

Restricted access