Europium chloride

As indicated later (see Section VI,8), on addition of the chloride of praseodymium, europium, or other lanthanides to mono- or poly-sac-charide phosphates in D20, the signals of carbon atoms substituted with phosphate groups are recognizable, as they are displaced, relative to the rest of the 13C-n.m.r. spectrum.155 However, this diagnostic method is not applicable to sulfated polysaccharides, as signal displacements were not observed on addition of praseodymium or europium chloride to a solution of a,/3-D-galactose 6-sulfate or its sodium salt.156... 

In addition to the coupled-signal method just described, phosphorylated carbon signals can be detected by use of praseodymium chloride, which displaces a- and /8-carbon resonances of a,/8-D-mannose 6-phosphate and a-D-mannosyl phosphate downfield, with little effect on other resonances. Europium chloride has analogous properties, except that the displacements are upfield. With certain polysaccharides, such as the O-phosphonomannan of Hansenula capsulata (29), the sig-... 

Z-isomer.56 The isomers of the cyclic phosphonate (36) were assigned from the effect of Eu(dpm)3 on the methyl signal.67 Shifts of the butyl signals of tributyl phosphate by europium chloride have also been recorded.58... 

Gallagher (154) studied with very great care the fluorescent behavior of europium chloride in D20—H20 mixtures. He gave qualitative confirmation to most of the findings of Kropp and Windsor however, three distinct differences were observed ... 

Freeman, Crosby, Lawson (13), Kropp, and Windsor 17, 18) had reported that hydrated europium chloride crystals and aqueous solutions of europium salts, respectively, showed considerable enhancement of ion fluorescence and lifetimes upon substitution of H2O by D2O, the latter workers have reported (37) that wet hydrocarbon solutions of the thenoyltrifluoroacetone chelate of europium showed no enhancement of quantum yield and lifetime upon replacing the H2O present by D2O. They suggested that whereas deuteration enhanced the fluorescent properties of the free ions by inhibiting nonradiative deactivation of the Do level, the quantum efficiency of Do luminescence obtained upon direct excitation of this level (JO, 11) is already so high in the fluorinated diketone chelates e.g. thenoyltrifluoroacetone) that deuteration of the environment should have little further enhancing effect. 

EuFi8N406Pi2C72Ht2, Europium(III), hex-akis(diphenyIphosphinic amide)-, tris(hexafluorophosphate), 23 180 EuCIs, Europium chloride, 22 39 EUCI8N4O2C49H27, Europium, (2,4-pentane-dionato)[5,10,15,20-tetrakis(3,5-dichlo-rophenyI)porphyrinato(2-)]-, 22 160 EuN30i3C8H,6, Europium(III), trini-... 

The FL spectra of Trp in water and dry ethanol are independent of the wavelength of the excitation light ( exc) The introduction of europium chloride, which forms complexes with tryptophan,2 (log p, = 4.82 0.07 (H20, 298 K)) quenches FL through PET,3,4 also it has no effect on the FL spectra of Trp in individual solvents. Taking into account the strong Stokes shift of the FL spectra of Trp in H20 (>. =... 

However, in 90% C2H5OH, excitation into the second and shorter-wavelength absorption bands of Trp does not lead to the bathochromic shift, rather, a short-wavelength shoulder emerges in the FL spectrum of Trp (Fig. 1, spectrum 1). In the presence of europium chloride, the shoulder at 295 nm transforms into a peak (Fig. 1, spectra 2 and 3), which is assigned to the S2 -> S0 radiative transition. 

CuMo04 COPPER MOLYBDATE 620 EuCI3 EUROPIUM CHLORIDE 664... 

CuO COPPER MONOXIDE 620 EuCI3 6H20 EUROPIUM CHLORIDE HEXAHYDRATE 665... 

For cytotoxicity experiments, a number of methods have been published (1,2,25,28,29). The principle of the assay is identical to that of chromium release (Fig 6). There are three methods to label the cells Europium-DTPA into cells after dextran sulphate treatment, incorporation (1,2,25) by electroporation incorporation of europium chloride DTPA (28) or by use of a new membrane penetrating fluorescent ligand (29) (Figure 8). All methods give comparable results to the use of a chromium label,however there are a number of distinct advantages besides the obvious radioactivity issue. Europium labelled cells once labelled can be stored for up to 3 -4 months at -20 C (27). The labelling procedure takes approximately 10-20 minutes. The label does not bind to any cellular components therefore has a higher release rate, thus shorter (2 instead of 4 hours) incubation times can be considered. 

Compound 8 (1.0 g, 2.24 mmol) was dissolved in THF (5 mL) in a 15-mL, round-bottomed flask and 1.0 M sodium hydroxide (2.46 mL) was added, dropwise. A solution of europium chloride hexahydrate (0.274 g, 0.75 mmol) in water (2 mL) was added and the flask was equipped with a reflux condenser. The reaction was heated to reflux for 3 h before excess methanol was added to end the reaction. The precipitate was removed by filtration, dried, dissolved in ether, filtered again, and precipitated into hexanes. The precipitate was isolated by filtration, which gave a red solid (750 mg, 66% yield). Anal, (found/calc for C69H54EUF9O9S6) C 53.55 (53.73), H 3.56 (3.53). 

Europium chloride (EUCI36H2O)(Ventron Co.) UO2(NO3)26H2O (T.T. Baker) and UO2(OAc)22H2O (Mallinckrodt Chemical Works) were used v/ithout further purification. Eu(0Ac)3 was prepared by the method described in the literature(16). 

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