Research Report
The Reduction of Rare-Earth Metal Halides with Unlike Metals - Wöhler's Metallothermic Reduction

Dedicated to Professor Rudolf Hoppe on the Occasion of his 85th Birthday, in Admiration for his Great Impact on Solid State Chemistry

Rare-earth halides may be reduced by rare-earth metals (conproportionation) and, as an alternative, by unlike metals such as alkali or alkaline-earth metals, a route first established for the production of rare-earth metals. It has great power for exploratory research subject to enhanced reactivity at lower temperatures and the formation of alkali halide flux for crystal growth. A large number of new compounds, ternary and higher, salt-like and (semi-)metallic including interstitially stabilized cluster compounds has been synthesized and characterized during the last decades.

Gerd Meyer, Z. Anorg. Allg. Chem. 2007, 633, 2537-2552.

Research Report
The Oxidation of Metals with Liebig Acids

Dedicated to Professor Dieter Naumann, Colleague and Friend, on the Occasion of his 65th Birthday

In Liebig's definition, an acid is a compound which contains one or more hydrogen atoms which may be substituted by metal atoms. Hence, reactions of Liebig acids in substance, excluding water or any other solvent, with non-noble metals yield salts and release hydrogen. In this sense, not only the classical mineral acids such as sulfuric or nitric acid, respectively, are Liebig acids. Rather, there is a large variety of organic compounds with, for example, HO- or HN-functions with acid constants that allow for substitution of the hydrogen atoms by a metal atom. Simple covalent hydrides like water and ammonia or even methane may also act as Liebig acids with conditions properly chosen. The ammonium ion, (NH4)+, represents a special case as it is available in a large variety of salts and may react as an acid/oxidant or as a (base)/reductant and is also a pseudo alkali-metal cation. The versatility of the ammonium ion is reviewed with special emphasis to its ability to function as a Liebig acid, i.e., reactions of, especially, ammonium halides with non-noble metals.

Gerd Meyer, Z. Anorg. Allg. Chem. 2008, 634, 201-222.

Superbulky Ligands and Trapped Electrons: New Perspectives in Divalent Lanthanide Chemistry

Spectacular developments in recent years, especially the discovery of an anionic complex of divalent lanthanum, in which the electron is trapped in a localized 5d1 SOMO (see structure of the anion of [K([2.2.2]crypt)][LaCp''3] (Cp''=1,3-(SiMe3)2C5H3); La red, C gray, Si black), have brought new impetus to the solution chemistry of divalent lanthanides.

Gerd Meyer, Angew. Chem. Int. Ed. 2008, 47, xxxx-xxxx; Angew. Chem. 2008, 120, xxxx-xxxx.

Chains of face-sharing osmium-centered cubes and square antiprisms
in the crystal structure of {Os3Sc12}Br16Sc with 15 cluster-based electrons and two electrons consumed by an Os-Os bond

Sina Zimmermann, Gerd Meyer, unpublished 2008

RuHo5I7: An Intergrowth of {Ru4Ho16}I20 and {Ho4}I8 ?

Kathrin Daub, Gerd Meyer, unpublished 2008.

Tantalum(IV) Iodide: Forgotten and Resurrected

Gerd Meyer, Rafal Wiglusz, Ingo Pantenburg, Anja-Verena Mudring, Z. Anorg. Allg. Chem., 2008, 634, 825-828.

Seven-coordinate ruthenium atoms sequestered
in praseodymium clusters in the chloride {RuPr3}Cl3

Nina Herzmann, Anja-Verena Mudring, Gerd Meyer, Inorg. Chem. 2008.

Facile synthesis of an iodine inclusion compound.
Molecular iodine in the anionic chains [I2@Pd2I6]2-

Christine Walbaum, Ingo Pantenburg, Gerd Meyer, Inorg. Chem. 2008.

Iodine molecules included in the crystal structure
of dibenzo-24-crown-8

Christine Walbaum, Ingo Pantenburg, Gerd Meyer, unpublished 2008.

Iodine molecules attached to CdI2 or HgI2 molecules
sequestered in benzo-18-crown-6

Ralph Striebinger, Christine Walbaum, Ingo Pantenburg, Gerd Meyer,
Z. Anorg. Allg. Chem. 2008.

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