Multiple dumbbell structures of vanadium–C60 clusters

Vanadium (V)–${\mathrm{C}}_{60}$ mixed clusters were produced by two laser vaporization methods. In the mass spectra of cationic ${\mathrm{V}}_n({\mathrm{C}}_{60}{)}_m^{+},$ the abundant clusters were produced at the composition of $\text{(n,m)=(1,1),}$ (1,2), (2,3), (3–4,4), and (5,5). This pattern is explicable in terms of a multiple dumbbell structure; V atom and ${\mathrm{C}}_{60}$ are alternatively piled up. The ionization energy and the reactivity of the dumbbell clusters toward ${\mathrm{O}}_2$ and CO show ${\mathrm{V}}_1({\mathrm{C}}_{60}{)}_2$ takes a structure of ${\mathrm{V}}_1{\mathrm{(\eta }}^6-{\mathrm{C}}_{60}{)}_2.$