Synthesis, characterization, and reactivity of iron(II) sandwich complexes.
Loading...
Date
Authors
Sturge, Kevin Craig.
Journal Title
Journal ISSN
Volume Title
Publisher
Dalhousie University
Abstract
Description
Reactions of ((arene)$\sb2$Fe) $\sp{2+}$ dications with carbanion sources AlR$\sb3$, RLi, and RMgX have been investigated. In reactions with AlR$\sb3$ (R = Me, Et) in CH$\sb2$X$\sb2$ (X = Cl, Br), monocationic ((arene) (cyclohexadienyl)Fe) $\sp+$ complexes are produced where the cyclohexadienyl ligand is derived from single net Et$\sp-$ (AlEt$\sb3$) or CH$\sb2$X$\sp-$ (AlMe$\sb3$) addition to an arene ring. Reactions with alkyllithium or Grignard reagents yield ((cyclohexadienyl)$\sb2$Fe) complexes for arene = benzene, p-xylene, or mesitylene; and ((arene) (cyclohexadienyl)Fe) $\sp+$ complexes for arene = pentamethylbenzene or hexamethylbenzene.
Mixed-arene iron dications of the general formula ((arene) (arene$\sp\prime$)Fe) $\sp{2+}$ have been synthesized and their reactivity towards carbanions and borohydride has been investigated. This investigation has revealed that there is a preference for addition at the less substituted arene ligand. These results are rationalized as occurring via a single electron transfer process rather than a nucleophilic mechanism.
Finally, X-ray crystallographic characterization of a number of the aforementioned compounds with previously reported structures has allowed an analysis of Fe(II) sandwich complexes containing cyclopentadienyl, cyclohexadienyl, pentadienyl, and arene ligands. This analysis ranks the four ligands with respect to their ability to $\pi$-bond to iron as: arene $>$ cyclohexadienyl $\simeq$ pentadienyl $>$ cyclopentadienyl.
Thesis (Ph.D.)--Dalhousie University (Canada), 1991.
Mixed-arene iron dications of the general formula ((arene) (arene$\sp\prime$)Fe) $\sp{2+}$ have been synthesized and their reactivity towards carbanions and borohydride has been investigated. This investigation has revealed that there is a preference for addition at the less substituted arene ligand. These results are rationalized as occurring via a single electron transfer process rather than a nucleophilic mechanism.
Finally, X-ray crystallographic characterization of a number of the aforementioned compounds with previously reported structures has allowed an analysis of Fe(II) sandwich complexes containing cyclopentadienyl, cyclohexadienyl, pentadienyl, and arene ligands. This analysis ranks the four ligands with respect to their ability to $\pi$-bond to iron as: arene $>$ cyclohexadienyl $\simeq$ pentadienyl $>$ cyclopentadienyl.
Thesis (Ph.D.)--Dalhousie University (Canada), 1991.
Keywords
Chemistry, Inorganic.