Electron affinities of d1 transition metal chloride clusters and onset of super halogen behavior

► Electron affinities and vertical detachment energies of MCln (M = Sc, Y, La; n = 1-5) reported. ► Superhalogens when n ⩾ 4. ► Bond energy of M-Cl about 5 eV in MCln (M = Sc, Y, La, n = 1-3). ► Multicenter bonding in MCl4 and MCl5- (M = Sc, Y, La).