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SYNTHESIS, CHARACTERIZATION, AND REACTIVITY OF BINUCLEAR AND MONONUCLEAR IRON SYSTEMS.

The photochemical fragmentation of Fp(η¹-CH₂C₆H₅) and Me₂Si[C₅H₄Fe(CO)₂(η¹- CH₂C₆H₅)]₂ (2) to give metal-metal bonded species and bibenzyl as products has been explored. Several singly-bridged binuclear iron complexes have been prepared, namely Me₂Si[η⁵-C₅H₄Fe(CO)(L)I]₂(L = CO; L = PPh₃; L = P(OPh)₃) and [η⁵-C₅H₅Fe(CO)I]₂[(PhO)₂PC₂H₄P(OPh)₂], and their structure explored by both spectroscopic means and X-ray analysis. The preparation of the new metal-metal bonded complex, [η⁵-C₅H₅Fe(CO)]₂[(PhO)₂PC₂H₄P(OPh)₂], is also reported. Selective alkylations and reductions of the diiodide were L = PPh₃ with n-BuLi, benzylmagnesium chloride, and LiAlH₄ have led to the preparation of mixed alkyl-iodide and alkyl-hydride compounds. Molecular and crystal structures are determined for Me₂Si[η⁵-C₅H₄Fe(CO)]₂[dppm], Me₂Si[η⁵-C₅H₄Fe(CO)]₂[dppp], and Me₂Si[(η⁵- C₅H₄)₂Fe₂(CO)₃][dppm]. Full details on the synthesis, characterization, and the electrochemistry of the binuclear complexes Me₂Si[η⁵-C₅H₄Fe(CO)]₂[L] (where L = dppm, dppe, dppp) is reported. Also complexes of the type Me₂Si[(η⁵-C₅H₄)₂Fe₂(CO)₃][L] have been isolated in the case of L = dppm and dppe. A series of tetranuclear complexes for L = dppe and dppp is presented. A variety of activated unsaturated compounds, including acrylonitrile, react with Fp(η¹- C₅H₅), where Fp = η⁵- C₅H₅Fe(CO)₂, to give [3+2]-cycloadducts in good yield. Stereospecific replacement of the Fp moiety in these cycloadducts by a -CO₂Me group with retention of configuration occurs in good yield by oxidation with ammonium cerium (IV) nitrate in carbon monoxide saturated methanol. This two-step sequence: (3+2)-cycloaddition followed by oxidation, renders Fp(η¹- C₅H₅) a synthetic equivalent of methyl 1,3-cyclopentadiene-5-carboxylate in cycloaddition reactions. Sequential reaction of η⁵-C₅Me₅Fe(CO)₂I with AgBF₄, cyclopentadiene, and finally triethylamine affords the new compound η⁵- C₅Me₅Fe(CO)₂(η¹- C₅H₅) in 75% yield. This complex has been characterized by X-ray diffraction and low temperature NMR spectroscopy.

Identiferoai:union.ndltd.org:arizona.edu/oai:arizona.openrepository.com:10150/187058
Date January 1983
CreatorsWRIGHT, MICHAEL EUGENE.
PublisherThe University of Arizona.
Source SetsUniversity of Arizona
LanguageEnglish
Detected LanguageEnglish
Typetext, Dissertation-Reproduction (electronic)
RightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.

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