Packing atomic metal cations with C 60: Mass spectrometric observation of M +(C 60) n with M = Sr and Mo and n = 0–4

Abstract

The atomic cations of Sr and Mo have been observed to add sequentially up to four molecules of C 60 in helium at 0.35 Torr and room temperature in the flow tube of a modified inductively coupled plasma/selected-ion flow tube (ICP/SIFT) tandem mass spectrometer. The available center-of-mass energy in collision-induced dissociation experiments of approximately 1.3 eV failed to remove C 60 from M +(C 60) 4. A structure is proposed for M +(C 60) 4 cations in which the bonding involves η 6 interaction of the metal with the C 60 ligands and η 2-to-η 2 interactions between the C 60 ligands.