Long-lived dications of Cu(H2O)2+ and Cu(NH3)2+ do exist!

Four recent Letters in this journal have contributed to a controversy over the possible existence of the monoligated copper dications Cu(L)(2+) with L = H2O and NH3. Here, it is shown that charge-stripping (CS) mass spectrometry can be used to generate both Cu(L)(2+) dications in high-energy collisions of the corresponding Cu(L)(+) monocations. Although both dications are thermodynamically unstable with respect to their charge-separation asymptotes, i.e., Cu(L)(2+) --> Cu+ + L+, they are kinetically stabilized by Coulomb barriers and their lifetimes extend at the very least into the microsecond regime. (C) 2001 Elsevier Science BN. All rights reserved.