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.

Elementares Chlor, Brom und Jod reagieren unter geeigneten Bedingungen mit aliphatischen, hydroaromatischen und aromatischen tertiaren Phosphinen im Mol-Verh. 1:1. Die Additionsverbindungen sind mit Ausnahme des (C6H11)3PJ2 und (C6H5)3PJ2 auserst feuchtigkeitsempfindlich. Auf Grund ihres salzartigen Verhaltens konnen sie als Phosphoniumsalze aufgefast werden.



Die Phosphindihalogenide setzen sich mit SbCl5, SbBr3 und HgJ2 im Sinne einer Halogen-Donator-Akzeptor-Reaktion um. Die dabei entstehenden Phosphoniumsalze zeigen die Leitfahigkeiten binarer Elektrolyte. Sie enthalten das Phosphoniumkation [R3PX]+. Wahrend Phosphindichloride und Phosphindibromide in Losung mehr als Neutralmolekeln vorliegen, wird fur Phosphindijodide in Losung eine Dissoziation in [R3PJ]+ und J−-Ionen bewiesen.



Aus Phosphindihalogeniden und Reinecke-Salz konnen in wasrigem Alkohol Phosphinoxyd-Reinecke-Saure-Additionsverbindungen im Verhaltnis 1:1, 2:1 und 4:1 dargestellt werden. Bei der Solvolyse von Tricyclohexylphosphindibromid in CH3OH bei Anwesenheit von Reinecke-Salz entstehen [(C6H11)3POCH3] [Cr(SCN)4(NH3)2] und (C6H11)3P(OCH3)2 · H[Cr(SCN)4(NH3)2].



Beim Umkristallisieren des Tricyclohexylphosphindijodides aus C2H5OH in Gegenwart von Sauerstoff entsteht [(C6H11)3PO]2 · HJ3.

Zur Konstitution und Solvolyse von tertiären Phosphindihalogeniden — R3PX2 —

Im Zusammenhang mit der Bildungsweise des FeMes2 werden die Trimesitylferrate LiFeMes3(dx)4 und Mg[FeMes3]2(thf)5,75 hergestellt. Bei der Reaktion von FeMes2 mit Phosphinen, Aminophosphinen und Phosphiten konnen Komplexverbindungen der Zusammensetzung FeMes2L und FeMes2L2 erhalten werden, die sich in ihrer Reaktivitat und im magnetischen Verhalten unterscheiden. Magnetische Momente und thermisches Verhalten werden mitgeteilt.



Dimesityl Iron Chemistry. I. Trimesityl Iron Compounds and Complexes with P-Donors



Concerned with the formation of FeMes2 the compounds LiFeMes3(dx)4 and Mg[FeMes3]2(thf)5.75 were synthesized. Phosphines, aminophosphines, and phosphites react with FeMes2 forming complexes FeMes2L and FeMes2L2, respectively. Magnetic and thermal behaviour are reported.

Zur Chemie des Dimesityleisens. I. Trimesitylferrate und Komplexbildung mit P-Donoren

Durch Reaktion von Trimesitylvanadium mit Lithiumorganylen, LiR (R = Ph, o-Tol, Dmop, Me, CPh3)1 , sind Complexe des Typs Li(thf)4 VMes3R zuganglich. Mit geeigneten Dilithiumverbindungen konnen auch verbruckte Zweiternvanadate wie Li2(thf)8V2-(μ-C6H4)Mes6 und Li2(thf)8V2(μ-C2)Mes6 erhalten werden. Die thermischen, magnetischen und spektralen Eigenschaften dieser neuen Verbindungen werden untersucht.



Arylvanadium (III) Compounds. VI. Preparation and Properties of Lithium Trimesityl organyl Vanadates



Trimesityl vanadium reacts with LiR (R = Ph, o-Tol, Dmop, CH3, CPh3) forming complexes Li(thf)4 VMes3R. With Li2C6H4 and Li2C2 the compounds Li2(thf) 8 V(μ-C6H4)Mes6 and Li2(thf)8V(μ-C2)Mes6 are obtained. All compounds are characterized by their thermal, magnetical, and spectral properties.

Arylvanadium(III)‐Verbindungen. VI. Darstellung und Eigenschaften von Lithium‐trimesityl‐organyl‐vanadaten(III)

Mesityl-phenolato-vanadium(III)-Komplexe: Synthese, Struktur und Verhalten

Aus Cyclohexylphosphin und Cyclohexyldichlorphosphin entsteht unter Abspaltung von Chlorwasserstoff Tetracyclohexyl-cyclotetraphosphin, das auf Grund differentialebullioskopischer Molekulargewichtsbestimmung in Benzol tetramer vorliegt.



Mit elementarem Halogen werden die PP-Bindungen des (C6H11P)4 gespalten, wobei Cyclohexyldihalogenphosphine C3H11PX2 (X = Brom und Jod) entstehen, die mit uberschussigem Halogen Verbindungen des Typs C3H11PX4 bilden. Auserdem wird die Darstellung des (C6H11)2PBr3 und des (C6H11)2PJ3 beschrieben.



Tetracyclohexyl-tetraphosphine is formed from C6H11PH2 and C6H11PCl2 under separation of hydrogen chloride. By differential ebullioscopic determinations of the molecular weight it has been shown that the compound is tetrameric in benzene.



By elementary halogen the PP-bonds of (C6H11P)4 are cleaved and cyclohexyl dihalogen phosphines, C6H11PX2 (X = bromine and iodine), are formed reacting with halogen in excess to compounds of the formula C6H11PX4. The preparations of (C6H11)2PBr and (C6H11)2PJ3 are described.

W. Seidel

Papers

Zur Konstitution und Solvolyse von tertiären Phosphindihalogeniden — R3PX2 —

Zur Chemie des Dimesityleisens. I. Trimesitylferrate und Komplexbildung mit P-Donoren

Arylvanadium(III)‐Verbindungen. VI. Darstellung und Eigenschaften von Lithium‐trimesityl‐organyl‐vanadaten(III)

Mesityl-phenolato-vanadium(III)-Komplexe: Synthese, Struktur und Verhalten

Tetracyclohexyl-cyclotetraphosphin und Cyclohexyl-halogenphosphine