Abstract
Relative reactivity of cyclic ethers, including epoxide, oxetane, tetrahydrofuran, and tetrahydropyran, was evaluated with their basicity and free energy of polymerization. The logarithm of relative reactivity, 1/rn , of m-membered ring ethers with i substituents to n-membered ring monomers with j substituents can be expressed by a linear combination of the differences in basicity, Δ(pKb)m·i-n·j, and in free energy, Δ(ΔG)m·i-n·j + γ where, α, β, and γ are constants. The changes in basicity and free energy of these compounds can be obtained as Here ak and bk (k = m, n) are constants, σ* is the polar substituent constant by Taft, and Δ(X)(m-n)·2(CH3) (X = ΔG, pKb) are the differences in basicity and free energy between dimethyl-substituted compounds of m- and n-membered rings, respectively.
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