Europium -2-thenoyltrifluoroacetone complex

A broad range of metal centers have been used for the complexation of functional ligands, including beryllium [37], zinc, transition metals such as iridium [38], and the lanthanide metals introduced by Kido [39], especially europium and terbium. Common ligands are phenanthroline (phen), bathophenanthrolin (bath), 2-phenylpyridine (ppy), acetylacetonate (acac), dibenzoylmethanate (dbm), and 11 thenoyltrifluoroacetonate (TTFA). A frequently used complex is the volatile Eu(TTFA)3(phen), 66 [40]. 

M. Aihara, M. Arai, and T. Taketatsu, Flow Injection Spectrofluorimetric Determination of Europium(III) Based on Solubilizing Its Ternary Complex with Thenoyltrifluoroacetone and Trioctylphosphine Oxide in Micellar Solution. Analyst, 111 (1986) 641. 

The mass spectra of the lanthanide complexes of thenoyltrifluoroacetone, [R(CF3C0CHC0C4H3S)3], have been obtained for samarium, europium, gadolinium, and terbium (Das and Livingstone, 1975). The spectra are similar and fluorine migration to the metal ion with concomitant loss of CF2 occurs. The species RFJ was observed for samarium, gadolinium, and terbium and RF was observed for the easily reduced ions samarium and europium. No oxidation of terbium to terbium(IV) occurred. A mechanism for the fragmentation has been presented. 

Rare-earth jS-diketonate complexes can be synthesized by extraction methods. Halverson et al. (1964a, 1964b) obtained Lewis base adducts of europium(III) j8-diketonates by equih-bration of an aqueous solution of europium(lll) nitrate with a solution of the -diketone (or its ammonium salt) and of the Lewis base in diethyl ether. As the Lewis base, trioctylphosphine oxide (topo), tributylphosphate (tbp) or dihexylsulfoxide (dhso) were used. The molar ratios Eu + diketone Lewisbase were 1 3 2. The complexes are formed in the ether layer, and could be obtained as viscous oils from the ether solution. Richardson and Sievers (1971) prepared tris complexes of 1,1, l,5,5,6,6,7,7,7-decafluoro-2,4-heptanedione by extraction of an aqueous solution of the decafluoroheptanedione in diethyl ether. The rare-earth chlorides were used in 10 to 50% excess in order to prevent the formation of the corresponding tetrakis complexes. [Eu(tla)3(phen)] was prepared by extraction of an aqueous solution of europium(III) chloride, 2-thenoyltrifluoroacetone and 1,10-phenanthroline with benzene (Melent eva et al., 1966). After separation of the benzene layer from the aqueous layer, the [Eu(tta)3(phen)] complex was precipitated by addition of petroleum ether to the benzene layer. 

---