We report results from a computational study of the binding in complexes formed from one of the transition-metal ions Sc+, Ti2+, or V3+, each of which has two valence electrons outside an argon core, and one of the second-row hydrides FH, OH2, NH3, BH3, or BeH2. The complexes that involve the electron-rich ligands FH, OH2, and NH3 have strong ion-dipole components to their binding. There are large stabilization energies for a-interactions that transfer charge from occupied lone-pair natural bond orbitals on the F, O, or N atom of the (idealized) Lewis structure into empty non-Lewis orbitals on the metal ions; these interactions effectively increase electron density in the bonding region between the metal ion and liganded atom, and the metal ions in these complexes act in the capacity of Lewis acids. The complexes formed from the electron-poor hydrides BH3 and BeH2 consistently incorporate bridging hydrogen atoms to support binding, and there are large stabilization energies for interactions that transfer charge from the Be-H or B-H bonds into the region between the metal ion and liganded atom. The metal ions in Sc+-BeH2, Ti2+-BeH2, Ti2+-BH3, and V3+-BH3 act in the capacity of Lewis acids, whereas the scandium ion in Sc+-BH3 acts as a Lewis base.