SYNTHESIS, STRUCTURE AND PROPERTIES OF VOLATILE LANTHANIDE PIVALATES

The detected volatility of lanthanide pivalates has drawn attention to the study of their synthesis, structure and properties. Lanthanide pi valates have been obtained as adducts MPiv(3) . 3HPiv and MPiv(3) . Ph en (M=La, Pr, Ce, Nd, Gd, Ho, Er, Yb; HPiv, pivalic acid; Phen, 1,10-p henanthroline) and hydrates MPiv(3) . mH(2)O (m=3-7). When heated, the adducts MPiv(3) . 3HPiv decomposed with the formation of MPiv(3) at t emperatures below 200 degrees C. The X-ray crystal structure of dimeri c complexes [MPiv(3) . 3HPiv] (M=Nd, Ce) has been determined. The comp ounds MPiv(3) . 3HPiv, MPiv(3) . Phen and MPiv(3) have been characteri zed by IR spectroscopy and thermal analysis. Mass spectrometry data ha ve demonstrated the oligomeric structure of MPiv(3) in the vapour phas e. The temperature dependence of the vapour density has been determine d for MPiv(3) (M=Nd, Er) in the range 330-370 degrees C by the flow me thod. It was found that kinetic factors strongly affected lanthanide p ivalate sublimation.