Eckhart K. G. Schmidt

Eine effiziente methode zur darstellung neuer komplexe des kations [(dicarbonyl)(ligand)(η5-cyclopentadienyl)-eisen]+☆

Abstract A simple new method is described for the generation of the (dicarbonyl)-(η 5 -cyclopentadienyl)iron cation (Fp + ). This coordinatively unsaturated species forms complexes of the type [LFp] + with various neutral ligands L (L = olefins, dienes, ketones, aldehydes, esters, nitriles, nitro compounds, acetic acid, tetrahydrofuran, dimethylformamide, dimethylsulfoxide, and triphenylphosphine).

Die synthese neuer kationischer (olefin)- und (dien)-(η5-cyclopentadienyl)eisen-komplexe durch ligandenaus-tauschreaktionen

Abstract Ligand exchange reactions provide an especially convenient access to synthetically interesting mono- and diolefin-complexes of the cationic (η5-cyclopentadienyl)iron. The complex [(dicarbonyl)(η5)-cyclopentadienyl)(tetrahydrofuran)-iron]+ (I), for which an efficient method of preparation has been developed, serves as an ideal starting material for the synthesis of new and known half-sandwich complexes. The relatively mild reaction conditions permit detection of yet unobserved, thermodynamically less stable complexes.

Über die bildung von β-halogenalkyleisenkomplexen bei der oxidativen addition von brom an (tetracarbonyl)(olefin)eisenkomplexe und den zerfall der σ-komplexe

Abstract Addition of bromine to (tetracarbonyl)(olefin)iron complexes at low temperatures leads to the formation of (tetracarbonyl)(β-bromoalkyl)iron complexes in a stereospecific way. These novel iron σ-complexes show hindered rotation around the carboncarbon bond and undergo β-elimination in a stereospecific manner. The same kind of σ-complexes are assumed intermediates responsible for the dehalogenation of vicinal dibromides by nonacarbonyldiiron.

Synthese, eigenschaften und carbonyl-insertions-reaktionen von tetracarbonyleisen(0)-komplexen para-substituierter styrole

Abstract The Fe(CO) 4 η 2 -complexes of para -substituted styrenes (substituent  H, CH 3 , OCH 3 , Cl, F) can be obtained in good yields. Complexation changes drastically the chemical shifts and coupling constants of the vinyl protons. Reaction of the complexes with one mole equivalent of bromine in methanol liberates styrenes, but using two equivalents esters and diesters are formed via intermediate complexes of iron(III). For these carbonyl insertion reactions no systematic influence of the substituent on yield and product distribution was observed.