Bulletin of the Korean Chemical Society

Korean Chemical Society (대한화학회)
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A New Substituent Constant $σ^{c+}4_s$;a Fit for π-Participation in Modified Hammett-Brown Equation

  • Published : 1996.04.20
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Abstract

A set of substituent constants, σc+, has been widely used comparing the stability of carbocation in super acid condition. Plotting of 13C chemical shifts of cationic carbon (Δδc+) against σc+ constants yields an excellent correlation with a good correlation coefficient (r=0.999) for a cyclopentyl cation system. But these σc+ constants show poor linearity in norbornenyl cations that well known to show homoallylic stabilization in a cationic condition. We calculated the new substituent constant, σc+π, and found that the new substituent constants give an excellent correlation in π- and πσ-participating cation systems.

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References

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