Ab initio and DFT calculations have been carried out to explore the thermodynamic and/or kinetic stabilities of M2+L complexes (M = Be, Mg, Ca, and Zn, L = formaldehyde, acetone, and DMSO). Based on the computational data, all of the investigated monoligated doubly charged metal cation complexes are expected to be observable in the gas phase. In addition to thermodynamic stability, the kinetic energy barriers further stabilize the monoligated doubly charged metal cations. Thermodynamically unstable complexes are stabilized by Coulomb barriers. Monoligated metal dications have been classified into metastable and thermodynamically stable species. Comparison with experiments indicates agreement for magnesium and calcium containing systems. (C) 2002 Elsevier Science B.V. All rights reserved.