The complexes of
vanadium(111) and oxovanadium(1V) with pentane-2,4-dione;
l,l,l-trifluoropentane-2,4-dione; 1,1,1,5,5,5-hexafluoropentane-2,4-dione;
l,l,l-trifluoro-5-methylhexane-2,4-dione; l,l,l-trifluoro-5,5-dimethylhexane-2,4-dine
1,1,1,2,2-pentafluoro-6,6-dimethylheptane-3,5-dione and
1,1,1,2,2,3,3-heptafluoro-7,7-dimethyloctane-4,6-dione have been prepared. The
volatility, thermal and chemical stability of the chelates have been examined
by simultaneous differential thermal and thermogravimetric analysis in dynamic
atmospheres of nitrogen, air and water-saturated nitrogen and air, in addition
to heating under vacuum to temperatures approaching 360�C. The vanadium(111)
chelates of the fluorinated β-diketones volatilized with little evidence
of decomposition even in air and were stable in the absence of air to
280-320�C. In contrast, the oxovanadium(1V)chelates partly decomposed during
volatilization at temperatures as low as 150�C, and completelydecomposed over the
temperature range 180-240�C.
Synthesis of Some of Fluorinated Benzimidazole Nucleosides