Terbium spectroscopy

In conclusion I should like to consider a few of the chemical investigations which might be accomplished in the rare earth field by Mossbauer spectroscopy. The study of nonstoichiometric oxides has been discussed earlier, but there is the problem of finding an appropriate doping nuclide for the praseodymium oxide system. The element most capable of following the changes in oxidation state of the praseodymium is terbium-159, which does have a Mossbauer state, however, with a rather broad resonance (58,0 k.e.v., = 0.13 nsec.). Nevertheless, with a sufiiciently... 

Figure 2.43 (a) [Lns] clusters, hydrogen atoms have been removed for clarity (b) view of the cluster where ligands have been removed for clarity [77]. (Reproduced from S. Petit, F. Baril-Robert, G. Pilet, C. Reber and D. Luneau, Luminescence spectroscopy of europium(III) and terbium(III) penta-, octa-and nonanuclear clusters with fS-diketonate ligands, Dalton Transactions, 34, 6809-6815, 2009, by permission of the Royal Society of Chemistry.)... 

Petit, S., Baril-Robert, F., Pilet, G, etal (2009) Luminescence spectroscopy of europium(lll) and terbium(lll) penta-, octa- and nonanuclear clusters widi -diketonate ligands. Dalton Transactions, 6809—6815. 

Chauvin, A.-S., Gumy, F., Imbert, D., and BunzU, J.-C.G (2004) Europium and terbium tris(dipicolinates) as secondary standards for quantum yield determination. Spectroscopy Letters, 37 (5), 517-532. 

Numerous, wide-ranging spectroscopic techniques will be presented in this volume, with the exception of nuclear magnetic resonance (NMR), which was the subject of Volumes 176, 177, and 239 of Methods in Enzy-mology, and mass spectrometry, which was the subject of Volume 193. Examples of techniques from each of three major areas, ultraviolet/visible spectroscopy, vibrational spectroscopy, and electron or electron/nuclear magnetic resonance, are presented in this volume. Also included are special topics like rapid-scan diode-array spectroscopy, terbium labeling of chromopeptides, and deconvolution of complex spectra that are covered in chapters in Section IV of this volume. 

McCaw CS, Murdoch KM, Denning RG (2003) Energy levels of terbium(III) in the elpasolite Cs2NaTbBrg. I. Luminescence and two-photon spectroscopy. Mol Phys 101 427 38... 

From Figure 17.3 it is clear that the history of discoveries falls into three different periods. The first, about 1800, was the time for the basic discoveries, yttrium and cerium the second, around 1840, resulted in four new elements, erbium, terbium, lanthanum and didymium. Not until the introduction of the spectroscopy in the middle of the 19 century and the development of improved separation techniques did the discoveries enter the third period, 1870-1910. Yet, the last REM, promethium, was not discovered until 1945. Some biographical information about the actual discoverers is given along with the different discovery descriptions below. 

Bunsen s investigation seemed to show that terbium does not exist But the argument is dubious. Spectroscopy was in its infancy and the method was very empirical. 

The lanthanide-nitrate interaction in anhydrous acetonitrile was investigated by means of conductimetry, vibrational spectroscopy, and luminescence measurements which are very sensitive to changes in the first solvation sphere of the metal ion (Bunzli and Choppin 1989). Conductimetiic data on 0.0001-0.01 M solutions of europium or terbium trinitrate in anhydrous acetonitrile indicate that no dissociation occurs. The vibrational spectra show the presence of coordinated acetonitrile and the nitrato group frequencies are consistent with bidentate anions of approximate C2v local symmetry (Bunzli et al. 1978). When the concentration of nitrate is increased, the formation of [R(N03) ] "b species (n>3) is clearly evidenced in the FT-IR spectra (Mabillard 1983). The coordination numbers determined for Nd, Eu, Tb and Er in solutions containing an excess of nitrate are constant (9.9 0.3) and correspond to the formation of pentanitrato [R(N03)5] species, in which the nitrate ions are bonded in a bidentate fashion and which do not contain any coordinated acetonitrile molecule. The strong nitrate/europium interaction is evidenced when water is added to acetonitrile solutions of europium trinitrate. The first two acetonitrile molecules are quantitatively replaced by water molecules, but the replacement of the remaining solvent molecules is difficult to achieve and requires... 

Information about the relative strength of the interaction between terbium and aqueous and non-aqueous solvents was obtained by Batyaev et al. (1975). Terbium perchlorate solutions (0.0036 M) in water, deuterated water, pyridine-water, n-propanol-water, acetonitrile-water, DMF-water, and methanol were studied by relaxation spectroscopy. An affinity series could be established, which is parallel to the donor number of the solvents ... 

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