Generation and electronic properties of lanthanide-cyclooctatetraene organometallic clusters in gas phase

Organometallic clusters of lanthanide (Ln = Nd, Er, Eu, and Yb) and 1,3,5,7 -cyclooctatetraene (C8H8) were produced by a combination of laser vaporizat ion and molecular beam methods. In the mass spectra of [Ln(n)(C8H8)(m)], co mpositions of m = n + 1 were magic numbers. From mass spectrometry, photoio nization spectroscopy, and photoelectron spectroscopy, we have concluded th at these magic-numbered clusters take multiple-decker sandwich structures i n which Ln atoms and C8H8 molecules are alternatedly piled up. These sandwi ch clusters are formed through ionic bonds composed of multiply charged cat ions [Ln(k+) (k = 2 and 3)] and multiply charged anions [C8H8h- (h = 1, 1.5 , and 2)].