Thesis

Mono and bimetallic s-block and zinc chemistry : new structures, new reactions and new concepts

Creator
Awarding institution
  • University of Strathclyde
Date of award
  • 2013
Thesis identifier
  • T13558
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • The topics discussed within this thesis are varied, but focus primarily on the unique reactivities and structural diversity which can be obtained when alkali metal reagents are combined with divalent magnesium and zinc mixtures. In chapter two, a family of homometallic anthracenolate complexes were synthesised by reaction of either mixed-metal or monometallic bases with tricyclic ketone anthrone. When an alkali metal is present in the initial base (in combination with magnesium or zinc or alone), dimers of formulation [(donor).M(C₁₄H₉O)]₂ (donor = TMEDA when M= Li or Na and donor = PMDETA when M=K) were isolated. When [(TMEDA).Bu₂Mg] or [(TMEDA).Et₂Zn] were reacted with anthrone, monomers of formulation [(TMEDA).Mg(C₁₄H₉O)(nBu)] and [(TMEDA).Zn(C₁₄H₉O)(Et)] respectively were obtained, and characterized fully in both solid state and solution. In the zinc complex, a TMEDA resonance exhibiting dynamic behaviour within the 1H NMR spectrum was investigated by variable temperature techniques. The zincates [(TMEDA)Na·(μ-TMP)(μ-tBu)Zn(tBu)] 2a and [(TMEDA)Na·(μ-HMDS)(μ-tBu)Zn(tBu)] were found to facilitate alkylation of both fluorenone and 2-benzoylpyridine in the unusual 6 position with respect to the oxygen atom, allowing crystallization of these 1, 6- adducts (when 2a was utilized). Use of [(TMEDA)Na·(μ-HMDS)(μ-tBu)Zn(tBu)] gave structural evidence of both 1, 2- and 1, 6- addition products in the reaction with 2-benzoylpyridine. After aqueous workup of these mixtures, ring tert-butylated products and the corresponding tertiary alcohol were produced, and separated by chromatography column. When the zincate [(TMEDA).Na(μ-TMP)(μ-Et)Zn(Et)] was reacted with fluorenone, a hexameric dimer (Na-9-Et-9H-Fluoren-9-olate)₆ was structurally characterized. The zincate 2a was also found to act as a single electron transfer reagent towards chalcone, resulting in a novel homocoupling product. The chemistry of potassium magnesiates in arene deprotonation and inverse crown formation was studied, in terms of both the active basic species and in new reactivities. The species [KMg(TMP)₂Bu]x was crystallized as a tetrameric, hexameric and polymeric aggregate, and found by a variety of NMR spectroscopic techniques to be the active base in formation of hexameric inverse crown complexes. It was then used to form a new inverse crown via deprotonation of naphthalene at the 2-position, trapping 6 monometallated units within a 24 membered [KNMgN]₆ ring. A new ferrocenophane [{Fe-(C₅H₄)}₂{K₂Mg₃(TMP)₂(THF)₂(toluene)₂}] was generated by reacting [KMg(TMP)₂Bu]x with ferrocene at reflux temperature. Two new polymeric species of consititution [KMg(TMP)(CH₂SiMe₃)₂] and [(Tol.)KMg(TMP)(CH₂SiMe₃)₂] were also crystallized.
Resource Type
DOI
Date Created
  • 2013
Former identifier
  • 1001524

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