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CurtinHammett principle
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Curtin-Hammett principle. intramolecular electron transfer ... Duan & Moeller, JACS, 2002, 124, 9368. Despite the 'doom' forecast by these values, the tetra ... – PowerPoint PPT presentation
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Title: CurtinHammett principle
1
Topics
Curtin-Hammett principle intramolecular
electron transfer cyclic voltammetry Nernst
equation steady state kinetics relative rates
of cyclization Thorpe-Ingold effect
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Despite the doom forecast by these values, the
tetra- hydropyran forms in a respectable
yield! How can this be understood?
Duan Moeller, JACS, 2002, 124, 9368
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intramolecular electron transfer
Curtin-Hammett principle exemplified
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What tool(s) is(are) available?Cyclic
voltammetry
Peak potential
Switching potential
Oxidation begins i.e., -e
Electron is beginning to be returned i.e., e
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Ep/2 (V)
1.42
1.40
1.10
1.20
1.30
Moeller Tinao, J. Am. Chem. Soc. 1992, 114,
1033-1041
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Communication between the electrophores
Note Use of Nernst equation application of
steady state kinetics
Notice that the Ep/2 values reflect increasing
k2, that they accord with the relative rates
of cyclization, viz., to
k8 k7 gt k6 gt k5 (gem methyls Thorpe-Ingold
effect) gt k5
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