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 dependent guided ion beam mass spectrometry. For Cu+(DXE)2, the only product formed corresponds to endothermic loss of a neutral ligand, while the Cu+ (DXE) 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 for these complexes of 2.74+/-0.08 and 1.87+/-0.06 eV, respectively. These values are compared with theoretical values obtained using density functional and second order Møller-Plesset perturbation, MP2, theories. We also compare our results with previously studied alkali cation-ether complexes. Although Cu+ and all alkali cations have 1S electronic ground states, the comparison shows different trends for Cu+ because of hybridization effects involving the valence d-electrons.