4c/3e Radical Cations with Cage‐Directed Configurations

The one-electron oxidation of (iso)[2.2.1.1]pagodanes leads to nonclassical 4c/3e radical cations of different persistence (min vs. h), as revealed by cyclic voltammetric and ESR studies as well as ab initio calculations. These radical cations with a “tight” (cyclobutanoid, 1•+) and an “extended” (π-complex, 2•+) configuration represent definite points on the D2h reaction coordinate of the [2 + 1] cycloaddition. Distances are given below in Å.