The reactions of Sc+ and Ti+ with D2O are studied as a function of translational energy in a guided ion beam tandem mass spectrometer. Both ions react to form three ionic products : MD(+), MO(+) and MOD(+) MO(+) formation occurs exothermically by dehydrogenation of D2O, even though this reaction Is spin forbidden for reaction of ground state M(+) in both systems. In the titanium system, the effect of electronic energy on product formation is probed by varying the conditions used for forming Ti+. The a(2)F state of Ti+ reacts much more efficiently than the a(4)F ground state at forming all three product ions. The relative reaction efficiencies are consistent with a recent study of the reverse reactions of MO(+) + D-2 [J. Phys Chem. 1993, 97, 544]. State-specific cross sections and the competition between the various products indicate that the reactions occur primarily through a low-spin state of a D-M(+)-OD intermediate. Thresholds of the cross sections for endothermic formation of all three product ions are consistent with values calculated by using previously measured bond energies.