In the low-bias regime we study here, an insulating molecule must have strong suppression of the transmission near the Fermi energy in all its conformers. The constrained structure of the bicyclo[2.2.2]octane frame makes them shorter than the equivalent butane-motif molecules (methylthiomethyl-functionalized C4-X, Si4-X, and Ge4-X). Despite being shorter molecules (shorter tunneling barriers), previously studied the bicyclo[2.2.2]octane systems have similar or lower transmission than their linear counterparts as testament to their superior insulating properties. The transmission is plotted against energy for select Si222, Ge222, and C222 molecules in ), however, there is some variation of the transmission depending on the conformation. The transmission of Ge222-Me is a bit higher than in the equivalent Si222-Me, and phenyl substituents may offer slightly lower conductance for germanium than methyl.