Pyramidal structures of lanthanide-C₆₀ clusters (Ln_n(C₆₀)_m: Ln = Eu and Ho)

A two-laser vaporization method produced novel lanthanide organometallic culsters, Ln_n(C₆₀)_m, consisting of lanthanide atoms (Ln; Ln = Eu and Ho) and C₆₀ molecules in the gas phase. The Ln_n(C₆₀)_m clusters were produced predominantly at compositions of (n,m) = (n, n + 3) [n = 1-4]. These stoichiometries revealed no chemisorption reactivity toward CCl₄ and O₂ reactants. The cluster having (1,4) composition was proposed to form a tetrahedral structure, in which a Ln atom was surrounded by four C₆₀ molecules. In larger clusters with (n, n + 3) composition, each Ln atom was in a local (1,4) group. Ln₁(C₆₀)_m clusters were charge-transfer complexes expressed as Ln₁^x+(C₆₀)_m^x+, and that Eu and Ho atoms existed as Eu²⁺ and Ho³⁺ ions, respectively.