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.

Zur Bildung von Mesitylmangan(II)‐ und Mesitylcobalt(II)‐ Komplexen

Dimesitylmagnesium wird als THF-Addukt, Mg(C9H11)2(THF)2, aus Mesitylmagnesiumbromid-Losungen gewonnen. Es ist monomer. Seine thermischen und komplexbildenden Eigenschaften werden mitgeteilt. Aus Mg(C9H11)2(C10H8N2) bildet sich leicht Mg(C10H8N2)2(THF)n.



Synthesis and Properties of Dimesityl Magnesium



Dimesityl magnesium is obtained from solutions of Mg(C9H11) Br in tetrahydrofuran. The isolated compound has the composition Mg(C9H11)2(THF)2 and is monomer in benzene. Its thermal and coordinative behavior is described. Mg(C9H11)2(C10H8N2) decomposes easily to Mg(C10H8N2)2(THF)n.

Synthese und Eigenschaften von Dimesitylmagnesium

Trimesitylaluminium wird als Tetrahydrofuran-Addukt, Al(C9H11)3(thf), durch Umsetzung von AlCl3(thf)2 mit Dimesitylmagnesium in Tetrahydrofuran gewonnen. Es last sich thermisch zu Al(C9H11)3 abbauen. Durch Komproportionierung mit Aluminiumchlorid bzw. durch stufenweise Organylierung sind auch Al(C9H11)Cl2(thf) und Al(C9H11)2Cl(thf) leicht zuganglich.



Synthesis of Mesityl Aluminium Compounds



Trimesityl aluminium, Al(C9H11)3(thf), is easily prepared from aluminium chloride and solutions of Mg(C9H11)Br or Mg(C9H11)2 in tetrahydrofuran. It loses tetrahydrofuran forming quite stable Al(C9H11)3. Al(C9H11)Cl2(thf) and Al(C9H11)Cl(thf) are obtained, too, from AlCl3 and Al(C9H11)3 or Mg(C9H11)2, respectively.

Synthese von Mesitylaluminium‐Verbindungen

Dimesitylzink wird solvensfrei durch Umsetzung von Zinkchlorid mit Dimesitylmagnesium in Tetrahydrofuran gewonnen. Die farblose Verbindung ist monomer, bildet Komplexaddukte mit 2,2′-Dipyridyl sowie Tetramethylethylendiamin und besitzt eine reaktive Metall-Kohlenstoff-Bindung. Seine thermischen und spektroskopischen Eigenschaften sowie Reaktionsbeispiele werden beschrieben.



Synthesis and characterization of dimesityl zinc



Dimesityl magnesium reacts with zinc chloride in THF solution forming dimesityl zinc. This compound is free of solvent and monomer in benzene. 2,2′-Bipyridine and tetramethylethylenediamine yield weak complexes. Thermal behaviour and spectroscopic properties of these compounds and some reactions of ZnMes2 are described.

Synthese und Charakterisierung von Dimesitylzink

Aus Organodichlorphosphinen R′PCl2 und sek. aliphatischen Aminen entstehen unter Abspaltung von HCl Dialkylamino-organochlorphosphine R2NPR′Cl, die mit Hilfe von Alkalimetallen reduktiv zu diaminodiorgano-diphosphinen R2N(R′)PP(R′)NR2 enthalogeniert werden konnen.



Bei Einwirkung von Brom wird die PP-Bindung unter Bildung entsprechender Brom-phosphine R2NPR′Br gespalten. Die Addition von Schwefel fuhrt zu Bis-P-sulfiden, die in verschiedenen Formen auftreten.



Dialkylamino-organochlorophosphines R2NPR′Cl are synthesized by reaction of organo-dichlorophosphines R′PCl2 with sec. aliphatic amines under elimination of hydrogen chloride. These compounds react with alkali metals yielding diamino-diorgano-diphosphines R2N(R′)PP(R′)NR2.



Bromine cleaves the PP-linkage giving the corresponding bromophosphines R2NPR′Br. By addition of sulfur diphosphines-disulfides are obtained with different configurations.

W. Seidel

Papers

Zur Bildung von Mesitylmangan(II)‐ und Mesitylcobalt(II)‐ Komplexen

Synthese und Eigenschaften von Dimesitylmagnesium

Synthese von Mesitylaluminium‐Verbindungen

Synthese und Charakterisierung von Dimesitylzink

Über Diamino‐diphosphine R2N(R)PP(R′)NR2