Low-valent (MeBDI)Al and (MeBDI)Ga and highly Lewis acidic cations in [(tBuBDI)M+⋅C6H6][(B(C6F5)4−] (M=Mg or Zn, MeBDI=HC[C(Me)N-DIPP]2, tBuBDI=HC[C(tBu)N-DIPP]2, DIPP=2,6-diisopropylphenyl) react to heterobimetallic cations [(tBuBDI)Mg–Al(MeBDI)+], [(tBuBDI)Mg–Ga(MeBDI)+] and [(tBuBDI)Zn–Ga(MeBDI)+]. These cations feature long Mg–Al (or Ga) bonds while the Zn–Ga bond is short. The [(tBuBDI)Zn–Al(MeBDI)+]