A series of unprecedented organoiron complexes of the formal oxidation states −2, 0, +1, +2, and +3 is presented, which are largely devoid of stabilizing ligands and, in part, also electronically unsaturated (14-, 16-, 17- and 18-electron counts). Specifically, it is shown that nucleophiles unable to undergo β-hydride elimination, such as MeLi, PhLi, or PhMgBr, rapidly reduce Fe(3+) to Fe(2+) and then exhaustively alkylate the metal center. The resulting homoleptic organoferrate complexes [(Me4Fe)(MeLi)][Li(OEt2)]2 (3) and [Ph4Fe][Li(Et2O)2][Li(1,4-dioxane)] (5) could be characterized by X-ray crystal structure analysis. However, these exceptionally sensitive compounds turned out to be only moderately nucleophilic, transferring their organic ligands to activated electrophiles only, while being unable to alkylate (hetero)aryl halides unless they are very electron deficient. In striking contrast, Grignard reagents bearing alkyl residues amenable to β-hydride elimination reduce FeXn (n = 2, 3) to clusters of...

Preparation, Structure, and Reactivity of Nonstabilized Organoiron Compounds. Implications for Iron-Catalyzed Cross Coupling Reactions

https://kops.uni-konstanz.de/bitstream/handle/123456789/10014/2000_CoordChemRev_203_325_Mecking.pdf;sequence=1

Cationic nickel and palladium complexes with bidentate ligands for the CC linkage of olefins

The combination of a magnesium anode with a sulfur cathode is one of the most promising electrochemical couples because of its advantages of good safety, low cost, and a high theoretical energy density. However, magnesium sulfur batteries are still in a very early stage of research and development, and the discovery of suitable electrolytes is the key challenge for further improvement. Here, a new preparation method for non-nucleophilic electrolyte solutions using a two-step reaction in one-pot is presented, which provides a feasible way to optimize the physiochemical properties of the electrolyte for the application in magnesium sulfur batteries. The first use of modified electrolytes in glymes and binary solvents of glyme and ionic liquid shows beneficial effects on the performance of magnesium sulfur batteries. New insights into the reaction mechanism of electrochemical conversion between magnesium and sulfur are also investigated.

Performance Improvement of Magnesium Sulfur Batteries with Modified Non‐Nucleophilic Electrolytes

Publisher Summary This chapter surveys the rapidly growing field comprising the chemistry of transition metal complexes containing ligands which are made up only of carbon atoms within their coordination spheres. The chapter describes metal complexes which contain linear or cyclic ligands of composition C n (n n ligands, in order of increasing carbon content of the ligand have been discussed. This is followed by a discussion on complexes of cyclic all-carbon ligands, such as [C 3 {Fe(CO) 2 Cp} 3 ] + . Complexes containing C n ligands associated with binuclear metal–metal bonded systems are followed by an account of metal cluster complexes containing C n ligands. It also includes hybrid complexes where a cluster supports a C n ligand also attached to a mononuclear metal–ligand fragment. The study is broadly based on a group-by-group approach and includes salient details of synthesis, properties, chemistry and electronic structure.

Transition Metal Complexes Containing All-Carbon Ligands

Open-Shell Organometallics as a Bridge between Werner-Type and Low-Valent Organometallic Complexes. The Effect of the Spin State on the Stability, Reactivity, and Structure.

Zugang zu Dipyridylmesitylnickel-Komplexen

Wahrend Dimesityleisen in unpolaren Losungsmitteln dimer vorliegt, spaltet es in starker polaren Losungsmitteln in solvatisierte Monomere auf. Mit Dimethoxyethan wurde ein Addukt isoliert und strukturell charakterisiert.



Chemistry of Dimesityl Iron. VIII Solution Behaviour of Tetramesityldiiron and Crystal Structure of Dimesityl(dimethoxyethane)iron



The dimer dimesityliron yields in polar solvents solvated monomers. The adduct with dimethoxyethane was isolated and characterized by X-ray structure determination.

Zur Chemie des Dimesityleisens. VIII. Lösungsverhalten von Tetramesityldieisen und die Kristallstruktur eines Dimethoxyethan-Addukts

Lithium-2,6-dimethoxyphenyl reagiert mit Vanadocen zu Li2V(Dmop)4. Ein entsprechender Vanadium(III)-Komplex LiV(Dmop)4 wird aus VBr3(thf)3 in Benzol erhalten. Beide Verbindungen bilden bei Ligandenabspaltung das dimere [V(Dmop)2]2. Fur analytische Zwecke wurde Hg(Dmop)Cl hergestellt.



Arylvanadium(III) Compounds. V. Formation of Vanadium Complexes with 2,6-Dimethoxyphenyl



Lithium 2,6-dimethoxyphenyl reacts with vanadocene forming Li2V(Dmop)4. With VBr3(thf)3 the vanadium(III) compound LiV(Dmop)4 is obtained. Both complexes decompose by ligand abstraction yielding [V(Dmop)2]2. For analytical purposes Hg(Dmop)Cl was synthesized.

Arylvanadium(III)‐Verbindungen. V. Zur Bildung von 2,6‐Dimethoxyphenylverbindungen des Vanadiums

Dipiperidinodicyclohexylbiphosphin bildet mit Ag-, Cu-, Hg-, Cd- und Zn-Salzen Biphosphinkomplexe, in denen der Ligand zweizahlig auftreten kann.



Die Verbindungen des Silbers und des Kupfers sind sehr stabil. Die Addukte mit Zink- und Cadmiumjodid werden leicht in Monophosphinkomplexe umgelagert, die auch aus Dipiperidinocyclohexylphosphin und den Metallsalzen zuganglich sind. Eine Mittelstellung nimmt der Quecksilberkomplex ein. Ein Teil der beschriebenen Verbindungen kristallisiert aus Benzol losungsmittelhaltig.



Dipiperidinodicyclohexyl-biphosphine reacts with monovalent Ag and Cu, divalent Hg, Cd and Zn ions forming complexes in which the biphosphine behaves as a bidentate ligand.



Whereas the Ag and Cu compounds are very stable, the adducts of Zn and Cd iodide are easily transformed to monophosphine complexes which can also be synthesized starting from monophosphine. The Hg biphosphine complex has a moderate stability.

Komplexbildung mit Amino‐Phosphinen. I Komplexverbindungen des Dipiperidino‐dicyclohexyl‐biphosphins und des Dipiperidino‐cyclohexyl‐phosphins mit d10‐Metallionen

W. Seidel

Papers

Zugang zu Dipyridylmesitylnickel-Komplexen

Zur Chemie des Dimesityleisens. VIII. Lösungsverhalten von Tetramesityldieisen und die Kristallstruktur eines Dimethoxyethan-Addukts

Arylvanadium(III)‐Verbindungen. V. Zur Bildung von 2,6‐Dimethoxyphenylverbindungen des Vanadiums

Komplexbildung mit Amino‐Phosphinen. I Komplexverbindungen des Dipiperidino‐dicyclohexyl‐biphosphins und des Dipiperidino‐cyclohexyl‐phosphins mit d10‐Metallionen

Zur Umsetzung von Dimesityleisen mit N‐Donatoren