Infrared spectra and thermal behaviour of salts of the bis(malonato) oxovanadium(IV) anion

Abstract

Infrared spectra of a series of anhydrous (Rb, Cs) and hydrated (Na, K, Ca, Sr, Ba, Pb, Ag, Tl) salts of the complex anion VO(C₃H₂O₄)₂]₂− were recorded and briefly discussed. The thermal behaviour of these compounds, as well as that of the corresponding diprotonated ethylenediamine cation, were investigated by TG- and DTA-methods in N₂-atmosphere and complemented with studies carried out in crucible furnaces in air. Pyrolysis intermediates and residues were characterized by IR spectroscopy and overall stoichiometries for the degradation processes were proposed. In most cases orthovanadate/VO₂ mixtures were obtained as final residues in N₂, whereas the corresponding divanadates were produced in air.