To increase the Lewis acidity of group 13 derivatives, introduction of positive charge is one of the effective methods. In order to stabilize the electron-deficient and low-coordinate species, bulky and electron-donating ligands are indispensable. Pentamethylcyclopentadienyl (Cp*) is a good candidate due to its flexible conformation and electron-rich nature, and has been utilized in stabilizing low-coordinate main group elements. In addition, strong s-donating N-heterocyclic carbene ligand is also applied to provide further kinetic and thermodynamic stability to the cationic group 13 derivatives. As an extension to our recent success in the isolation of low-coordinate boron dication, aluminum contact ion pairs are synthesized and structurally characterized. Several pentamethylcyclopetadienyl group 13 complexes are also synthesized. Reactivity studies these group 13 complexes will also be discussed.