Erbium oxidation states

Erbium has a +3 oxidation state that easily combines with the halogens and oxygen. The X here can be used to represent the hahde ion combining with the metaUic ion of erbium, as follows ... 

Polarographic studies gave no evidence for the existence of the bivalent oxidation states of selected actinides in acetonitrile solution. Only one wave corresponding to reduction of americium(iii) or curium(iii) to the zero-valent state was observed and experiments with berkelium(iii) and einsteinium(iii) failed to give conclusive results because of rapid radiolysis of the acetonitrile solution. A study of the electrochemical reduction of americium, thulium, erbium, samarium, and europium showed that the elements did assume the bivalent state with the actinide bivalent cations having a smaller stability than the lanthanides. The half-wave potential of nobelium was found to be —1.6 V versus the standard hydrogen electrode for the reaction... 

Photoluminescence excitation (PLE) spectroscopy was carried out at 77K on oxidized porous silicon containing iron/erbium oxide clusters. The novel PLE spectrum of the 1535 nm Er PL band comprises a broad band extending from 350 to 570 nm and very week bands located at 640, 840, and 895 nm. The excitation at wavelengths of 400 - 560 nm was shown to be the most effective. No resonant PLE peaks related to the direct optical excitation of Er by absorption of pump photons were observed. The lack of the direct optical excitation indicates conclusively that Er is in the bound state and may be excited by the energy transfer within the clusters. 

Complexes between some lanthanides in a low oxidation state and olefins were isolated by W.J. Evans et al. (1978a, 1981b). Cocondensation of lanthanum, neodymium, samarium or erbium metal with butadiene or 2,3-dimethylbutadiene at — 196°C in a metal vaporization reactor produces a brown solid, which can be extracted by toluene and tetrahydrofuran yielding soluble brown products with the empirical formulas R(C4H4)j for R = Nd, Sm, Er, and R[(CH3)2C4H4]2 for R = La, Er. For these complexes the following three formulas have been suggested ... 

For ninety years samarium, europium, and 5dterbium were the only accessible divalent rare earths in molecular organometalhc chemistry. However, the past two decades have witnessed the addition of scandium(II), yttrium(II), lanthanum(II), cerium(II), neodymium(II), dysprosium(II), hohnium(II), erbium(n) and thulium(II) in a molecular context.Thus 12 of the 17 rare earths are now known in the divalent state in an organometalhc context and no other area of chemistry has seen such a dramatic expansion in the number of available oxidation states. It would therefore seem to be only a matter of time before divalent states are extended to the remaining REs. An extensive palate of... 

Laboratory. The isotope produced was the 20-hour Fm. During 1953 and early 1954, while discovery of elements 99 and 100 was withheld from publication for security reasons, a group from the Nobel Institute of Physics in Stockholm bombarded with O ions, and isolated a 30-min a-emitter, which they ascribed to 100, without claiming discovery of the element. This isotope has since been identified positively, and the 30-min half-life confirmed. The chemical properties of fermium have been studied solely with tracer amounts, and in normal aqueous media only the (III) oxidation state appears to exist. The isotope and heavier isotopes can be produced by intense neutron irradiation of lower elements such as plutonium by a process of successive neutron capture interspersed with beta decays until these mass numbers and atomic numbers are reached. Twenty isotopes and isomers of fermium are known to exist. Fm, with a half-life of about 100.5 days, is the longest lived. °Fm, with a half-life of 30 min, has been shown to be a product of decay of Element 102. It was by chemical identification of Fm that production of Element 102 (nobelium) was confirmed. Fermium would probably have chemical properties resembling erbium. 

The far-infrared and visible spectra of erbium oxide have been observed by Bloor et al. (1970) about the antiferromagnetic state at 3.4 K. The complex spectra can be interpreted in terms of ions on two nonequivalent sites. The changes in the visible absorption spectrum, together with changes in phonon frequencies, are attributed to the presence of the exchange fields and a magnetostrictive expansion of the crystal lattice in the ordered state. 

The lutetium hahdes (except the fluoride), together with the nitrates, perchlorates, and acetates, are soluble in water. The hydroxide oxide, carbonate, oxalate, and phosphate compotmds are insoluble. Lutetium compounds are all colorless in the solid state and in solution. Due to its closed electronic configuration (4f " ), lutetium has no absorption bands and does not emit radiation. For these reasons it does not have any magnetic or optical importance, see also Cerium Dysprosium Erbium Europium Gadolinium Holmium Lanthanum Neodymium Praseodymium Promethium Samarium Terbium Ytterbium. 

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