Europium structure

A series of quaternary europium structures containing two edge-shared tetra-hedra, see Fig. 14.1c), have been synthesized with a general formula... 

However, it may seem that we have ignored the m, n, and p odd combinations that are also possible. For example, in jamesonite, Fe"Pb4Sb5Si4 [80], the mnp values are 034 (or 068), respectively (assuming one Fe(II) = 2 Cu(I)). We have successfully substituted europium into the structure to create a congru-ently melting, semiconducting FePb2Fu2Sb6Si4 [79]. This has a value of A B =... 

Most monochalcogenides of the Group 3 metals adopt the rock salt (NaCl) structure. Note that the crystal chemistry of divalent europium is very similar to that of the alkaline earths, particularly strontium, as the radius of Eu is almost the same as that of Sr ". For the Yb compounds, the cell dimensions are practically identical with those of the Ca compounds. 

Figure 9.55 A carbostyril-DTPA europium chelator is a strong enhancer of lanthanide luminescence. The chemical structure and three-dimensional structure of the chelator are shown.

Wedged octahedral structure for 1 1 adduct of tristdi-pivalomethanato)-europium(III) and 3,3-dimethyl-thietane- 1-oxide... 

Rare-earth elements have been largely used in these studies. Among them, europium (III) was considered owing to its unusual electronic structure. Eu3+-ion-modified TiOz samples were prepared by a chemical coprecipitation-peptization method [156], which consists of prehydrolysis of TiCl4 by frozen distilled water. The Eu203 powder was added to the above solution to produce a transparent aqueous solution according to the required Eu3+ modifying content (Eu3+ ion equivalent to 3.0 at% of Ti in bulk solution). 

A bit of a chemical application arose in our attempts to find a monochromatic source or absorber. Since EuF. > has fiuorite structure, there should be no quadrupole splitting. When a spectrum was taken of a commercial sample of EUF2 it was found that the europium present was essentially completely trivalent. The experimental spectrum is shown in Figure 9. 

The resolution of the PDB 1X8W crystal structure does not allow identification of magnesium ions. However, heavy atom [europium (Eu) and iridium. 

The structure is tentative, but it is known that (1) europium ions prefer an octahedral geometry, (2) they complex well with ammonia, and (3) (in this case) two naphthalene units are involved (Stevenson et al. 1999). 

The very useful lanthanide shift reagents, which facilitate analysis of molecular stereochemistry because of their line-broadening characteristics in NMR spectra, were studied when bound as a chelate complex to thietanes. X-Ray analysis of the adduct 3,3-dimethylthietane 1-oxide with tris(dipivalo-methanato)europium(III) [Eu(dpm)3] revealed the structure of a seven-coordinate complex (271). ... 

Cario, L., Lefond, A., Palvadeau, A., Deudon, P., and Meerschault, C. (1999). Evidence of a mixed valence state for europium in the misfit layer compound [(EuS)i.5]i. i5NbS2 by means of a superspace structural determination, Mossbauer spectroscopy and magnetic measurements. /. Solid State Chem. 147, 58-67. 

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