Mass spectrometric study of thermal stability of copper(II) bis(dipivaloylmethanate) vapour

Abstract

The processes of thermal destruction of copper(II) bis(dipivaloylmethanate) (Cu(dpm)2) in the temperature range 150~176were studied by using a two-temperature variant of a double chamber Knudsen cell, with mass spectrometric recording of the gas-phase composition. The temperature range of stability of the vapour of the complex in vacuum was determined, as were those of its mixtures with oxygen in different proportions. The temperature dependence of the rate constant of the thermolysis of (Cu(dpm)2) vapour was obtained. The thermal stability of Hdpm vapour and the influence of oxygen on the thermolysis of the ligand were studied.

X-ray photoelectron study of electron density distribution in palladium(II) β-diketonate complexes

“…Pd3d 3/2, 5/2 spectra. As is known, vacuum sublimation of -diketonate complexes can lead to decomposition of the latter [13,14]. Compounds with trifluoromethyl substituents in the ligand proved to be the least stable complexes from the series under study.…”

“…Thus increased net electron density (decreased energy of the Pd3d 5/2 level) correlates with the increased vaporization enthalpy. Substitution of alkyl by phenyl radicals in chelate ligands lowers the volatility of the compounds [13,14] and hence leads to lower binding energies of the core levels of the metal atom and higher enthalpies (Fig. 5).…”

Mass spectrometric study of gas-phase thermal stability of yttrium(III) tris(dipivaloylmethanate)

“…The gas-phase composition at the outlet from the reaction zone was determined mass spectrometrically. The whole system has been described in detail in [6].…”

“…4) Carbon dioxide (M/Z=44) and carbon monoxide (M]Z=28) are the main reaction products in oxygen, the fraction of the latter being greater than in the decomposition of Y(dpm)3 vapour without oxygen. Since the thermal stability of the ligand is lower than that of Y(dpm)3 in oxygen, the appearance of carbon dioxide and carbon monoxide among the thermolysis products is quite natural: they result from ligand thermolysis in oxygen [6].…”

“…We recently reported [6] the thermolysis of Cu(dpm)2 and Hdpm vapour under different conditions, using the same method. The system of injection of the vapour of the substances under study was described in detail.…”