Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Á. Gömöry x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

The donor strength of oxygen atoms in the Si−O−C and Si−O−Si groups has been studied by Mössbauer spectroscopy, using SnI4 as acceptor. At 80 K trimethylalkoxysilanes and the disiloxanes studied show characteristic isomer shifts on the basis of which the existence of pentacovalent SnI4·D and hexacovalent SnI4·D2 may be assumed. The changes in isomer shift due to the first and second oxygen atoms are −0.60 and −0.55 mm/sec, respectively. The coordination number is determined by the steric requirements of the donor relative to the coordination sphere of the acceptor, provided that the donor strength is sufficiently high. No donor-acceptor interactions have been observed with compounds of the-(OSiR2)-O-type. In the case of hexamethyldisiloxane, iodine is displaced from the coordination sphere. No quadrupole splitting has been observed in any of the cases studied. Thus the ratio of point charges assignable to the iodine and the donor oxygen atom is 6:1 for the trigonal bipyramidal arrangement; for a tetragonal pyramidal structure the angle between the xy plane and the Sn−I bond is ∼35°.

Restricted access

On the oximine complexes of transitionmetals

Part CXIX. Thermal and spectral studies on Ni(Diox.H)2 type chelate compounds

Journal of Thermal Analysis and Calorimetry
Authors: Cs. Várhelyi Jr., G. Pokol, Á. Gömöry, A. Gănescu, P. Sohár, G. Liptay, and Cs. Várhelyi

Abstract  

Fourteen chelates of the type [Ni(II)(Diox.H)2], ((Diox.H)2: various α-dioximes) have been studied by means of FTIR, NMR, MS data and various thermoanalytical methods (TG, DTA, DTG, DSC). In some cases kinetic parameters of the thermal decomposition of the complexes were also calculated using Zsak’s ‘nomogram method’. The mechanism of the decomposition processes was characterised on the basis of mass spectra.

Restricted access