Collision-induced dissociation and theoretical studies of Cu+-dimethoxyethane complexes

Collision-induced dissociation of the dimethoxyethane (DXE) complexes with copper ions, Cu+(DXE)(n), n = 1 and 2, is studied using kinetic energy depe ndent guided ion beam mass spectrometry. For Cu+(DXE)(2), the only product formed corresponds to endothermic loss of a neutral ligand, while the Cu+(D XE) complex dissociates by several competitive channels. The cross-section thresholds for single ligand loss are interpreted to yield 0 and 298 K bond energies for Cu+-DXE and (DXE)Cu+-DXE after accounting for the effects of multiple ion-molecule collisions, internal energy of the reactant ions, and dissociation lifetimes. We find absolute 0 K bond dissociation energies fo r these complexes of 2.74 +/- 0.08 and 1.87 +/- 0.06 eV, respectively. Thes e values are compared with theoretical values obtained using density functi onal and second order Moller-Plesset perturbation, MP2, theories. We also c ompare our results with previously studied alkali cation-ether complexes. A lthough Cu+ and all alkali cations have S-1 electronic ground states, the c omparison shows different trends for Cu+ because of hybridization effects i nvolving the valence d-electrons. (J Am Soc Mass Spectrom 2001, 12, 480-489 ) (C) 2001 American Society for Mass Spectrometry.