Reactivity of niobium-carbon cluster ions with hydrogen molecules in relation to formation mechanism of Met-Car cluster ions

Niobium-carbon Met-Car cluster ion ([([Nb.sub.n][C.sub.m]).sup.+]) is prepared with every combination of n and m in the gas phase by the laser vaporization technique. A dehydrogenation-controlled formation mechanism of niobium-carbon Met-Car cluster ions is described based on the [H.sub.2] affinity of [([Nb.sub.n][C.sub.m]).sup.+].