GUIDED ION-BEAM DETERMINATION OF THE CO-H-2 BOND-DISSOCIATION ENERGY()

A guided ion-beam tandem mass spectrometer with a flow tube ion source is used to determine the 0 K bond dissociation energy of Co+-H-2 from ligand exchange of CoCH4+ with D-2 and from collision-induced dissoci ation (CID) of CoH2+ + Xe. Given D-0(Co+-CH4) = 0.93 +/- 0.06 eV deter mined in our labs, the endothermicity of the ligand exchange reaction provides D-0(Co+-D-2) = 0.74 +/- 0.07 eV. The direct CID of CoH2+ proc ess yields D-0(Co+-H-2) = 0.82 +/- 0.11 eV. After zero-point energy co rrections, the average of these two results yields 0.76 +/- 0.10 eV. T his value agrees nicely with those determined by equilibrium methods a nd theory.