Di‐tert‐butylallenyliden‐Komplexe des Eisens

Abstract

Di-terf-butylallenylidene Complexes of Iron The synthesis of a tetracarbonyl(di-tert-butylallenylidene)iron(O) complex (1) is reported. It can be transformed to an octacarbonyl-p-(di-tert-butylallenylidene)-diiron(O) compound 2 and reactsthermally to an allenylidenetriiron derivative Fe,(CO)loC3(tBu)2 3. The synthesis of 1 via a trimethylamine oxide-induced substitution of CO with di-tert-butylpropargylate residues is accompanied by the formation of (C0)4Fecomplex 4, which has been characterized by an X-ray analysis.Der Allenylidencarben-Rest fungiert in Ubergangsmetallkomplexen als terminaler Ligand", als p2-bruckenstandiger Zwei-Elektr~nen-~-~) oder als p3-Vier-Elektronendonor '). In Eisensystemen wurden Carbenteilchen terminal gebunden 6, oder wie Methylen-und Vinylidenreste in p2-Bruckenstell~ng~~~) aufgefunden.Zur Erkundung des Bindungsverhaltens von Allenyliden-Fragmenten in Carbonyleisen-Verbindungen wurde ein Darstellungsweg dieser ungesattigten Spezies nach G1. (1)

Synthesis of Diiron Bridging Allenylidene Complexes Cp*2Fe2(μ-CCCR1R2)(μ-CO)(CO)2 (Cp* = η5-C5Me5) via Nucleophilic Addition to the Diiron Ethynediyl Complex (μ-C⋮C)[FeCp*(CO)2]2 and Their Conversion to Cationic μ-Vinylcarbyne and μ-Vinylidene Complexes

“…Dehydration of a γ-hydroxyvinylidene intermediate, which is formed by treatment of a metal complex with a propargyl alcohol derivative, is the only systematic preparative method for mononuclear allenylidene complexes . Further interaction with a labile metal species would lead to polynuclear complexes (Chart ). 3c-e However, such examples are very few, and no other rational synthetic method for dinuclear complexes is available until now. A limited number of previous studies have revealed two types of coordination modes: symmetrical μ-η 1 :η 1 ( A ) and side-on μ-η 1 :η 2 ( B ).…”

Activation of methanol in the reaction of [Fe3(CO)12] with 1-phenylprop-2-yn-1-ol; crystal structures of and chemical relationships between [Fe3(CO)9(μ-CO){(CC C(H)Ph}] and [Fe2(CO)6{Ph(H)CCCHC(OMe)O}]

“…Other triiron allenylidene derivatives (e.g. complex 4d, 8 Table 2) have been obtained through reaction routes not involving clusters and/or dehydration of propargyl alcohols. 8, 9 Little is known of the chemistry of the allenylidene complexes of type 4; 10 the formation of 5 represents a new example of their reactivity.…”

13C and 19F NMR chemical shifts of the iron carbene complex (CO)4FeCF2 – A case study at DFT level

“…One might compare the calculated value of 1b with the complex (CO) 4 Fe@C@C@C[C(tBu) 2 OC(O)O] [37], where the ligand is equatorial. A rather short bond distance (1.80 Å) was observed in experiment.…”