SYNTHESIS AND CHARACTERIZATION OF BAX2.18-CROWN-6 COMPLEXES - BARIUM BIS(1,1,1,5,5,5-HEXAFLUOROPENTANE-2,4-DIONATE).18-CROWN-6, A NONHYGROSCOPIC, THERMALLY STABLE, VOLATILE BARIUM COMPOUND

The synthesis of a series of BaX2.18-crown-6 complexes (X = hfac, tclac, tfac, thd, acac, O2CCF3, O3SCF3, O2CCH3, Cl, Br, I, NO3, OH and SCN) and BaX2 compounds (X = tclac, tfac, O2CCF3 and O3SCF3) is described. The BaX2.18-crown-6 complexes have been characterized by melting point determinations, elemental analysis and NMR spectroscopy. Their thermal stability and volatility at reduced pressure have been investigated. Barium bis(1,1,1,5,5,5-hexafluoropentane-2,4-dionato).18-crown-6, Ba(hfac)2.18-crown-6, appears to be a non-hygroscopic, thermally stable, sublimable solid. This compound has also been characterized by mass spectrometry. The 18-crown-6 complexes of BaI2, Ba(SCN)2, Ba(O2CCF3)2 and Ba(O3SCF3)2 are involatile and thermally stable up to 200-degrees-C. The 18-crown-6 complexes of BaX2 with X = Cl, Br, OH, NO3, O2CCH3, acac, tclac, tfac and thd dissociate upon heating between 80 and 200-degrees-C. In the complexes, with X = Cl, Br, NO3, OH and tfac, loss of 18-crown-6 is accompanied by some co-evaporation of the barium compound.