Abstract: The relative heats of formation of a series of 2-substituted 4, 4-dimethyl-l, 3- dioxolenium ions have been measured calorimetrically in concentrated sulfuric acid. The relative heats of formation of some tetrahydrofuryl,-pyryl, and 1, 3-dioxenium ions have also been measured. A significant Baker-Nathan order has been observed. Replacement of a methyl group by phenyl or vinyl results in a less exothermic heat of formation for the ion. ...
