Darren A Makeiff

University of British Columbia - Vancouver, Vancouver, British Columbia, Canada

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Publications (5)27.19 Total impact

  • Darren A Makeiff, John C Sherman
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    ABSTRACT: A six-bowl carceplex that entraps seven guest molecules, 5.(DMSO)7, was synthesized and characterized. The dynamics of the host shell was studied in solution in the absence and presence of water. A multiple-molecule template was found to drive the formation of 5.(DMSO)x.G(7-x) (G = DMA, DMF; x = 5-7). Higher selectivity was found for species containing greater numbers of DMSO molecules.
    Journal of the American Chemical Society 10/2005; 127(35):12363-7. · 10.68 Impact Factor
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    ABSTRACT: A free-standing simple enol has been generated inside a carceplex. Rates of ketonization under various conditions were determined; ketonization is extremely slow as compared to the rate in solution. Complexed water is required, and the mechanism proceeds via formation of an enolate followed by protonation at carbon by the same molecule of water that removed the proton from the enol. Acid or base retards ketonization by removing water from the cavity.
    Journal of the American Chemical Society 09/2003; 125(32):9558-9. · 10.68 Impact Factor
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    Darren A Makeiff, John C Sherman
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    ABSTRACT: The template effect in the formation of a trimer carceplex using 1-3 molecules as templates is explored. Thirteen different templates were studied and template ratios were measured for templates of like and unlike molecularity. Five transition-state models were studied for their binding abilities to see if these mirror the template ratios. The chemical shifts of the guests and the thermodynamic and kinetic values for templation suggest that binding is key, often tight, and that the guest determining step is formation of the last covalent bond. The molecular dynamics of guests as well as the conformational dynamics of both hosts and guests further addresses nature of the recognition between host and guest. Finally, we were surprised to discover that water can bind reversibly to the trimer carceplexes, which will have ramifications to any inner phase reactions conducted inside the cage.
    Chemistry 08/2003; 9(14):3253-62. · 5.83 Impact Factor
  • Darren Makeiff, John C. Sherman
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    ABSTRACT: ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
    ChemInform 11/2000; 31(45).
  • Darren A. Makeiff, Douglas J. Pope, John C. Sherman
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    ABSTRACT: We report a study of the template effect in the formation of tetramethylene-bridged hemicarceplex 7·guest. Two tetrol cavitands were bridged with 1,4-dibromobutane in the presence of suitable template (guest) molecules in N-formylpiperidine as solvent. Selectivity was observed when competing templates were present during the reaction:  the relative templating abilities (template ratios) of 30 different guest molecules range by 3600-fold, and manifest a significant preference for para-disubstituted benzenes. Twenty-one of the 30 hemicarceplexes used in this templation study are new. The trend in guest selectivity is markedly different from previous studies in which smaller cavities (e.g., carceplex 2·guest) are formed. In such studies, capsule 3·guest was a good transition state model, whereas this is not the case in the present work.
    Journal of The American Chemical Society - J AM CHEM SOC. 02/2000; 122(7).

Publication Stats

24 Citations
27.19 Total Impact Points

Institutions

  • 2000–2005
    • University of British Columbia - Vancouver
      • Department of Chemistry
      Vancouver, British Columbia, Canada