Enhanced axial–equatorial enthalpy differences in the methyl adamantanes
Abstract
Analysis of the thermodynamic parameters for the isomerization with AlBr3 of 2-methyl- to 1-methyl-adamantane, ΔGI0(298)–2·47 ± 0·19 kcal mol–1, ΔHI0–3·37 ± 0·11 kcal mol–1, ΔSI0–3·0 ± 0·3 cal mol–1 deg–1, reveals an enhancement of the total axial methyl strain of 0·9 kcal mol–1 in the rigid adamantane system over that typical of cyclohexanes.