A compact supersonic source is used in conjunction with a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer to generate and study the gas-phase reactivities of V14C12+ and V14C13+ Sequential reactions with up to 8 H2O molecules result in the formation of V14C12,13(OH)(2)(H2O)(6)(+) and V14C13(OH)(4)(H2O)(4)(+) by loss of H-2 or attachment of H2O. Both ions are observed to attach up to 8 CH3CN molecules. In light of an earlier study which indicated that Nb4C4+ has a slightly distorted 2 x 2 x 2 cubic structure, these results provide evidence for the proposed 3 x 3 x 3 cubic structure of V14C13+ where the 8 metals in the corners are the active binding sites. The similarity of the reactivity of V14C12+ suggests an analogous structure.