Electronic effects in cyclobutadiene radical cations
Abstract
The e.s.r. spectra of the cis-and trans-radical ions cyclo-Me2But2C4˙+, obtained from methyl-t-butylethyne, can be interpreted in terms of the breaking of the degeneracy of the molecular orbitals in the trans-isomer by more powerful electron release from the t-butyl groups than from the methyl groups.