Fullerenes with metal atoms substituted into the carbon framework have been observed in laser ablation studies of electrochemically prepared C 60/Pt or C 60/Ir(CO) 2) films that contain polymeric, covalently bound chains: ⋯C 60ML xC 60ML xC 60ML x ⋯ (ML x = Ir(CO) 2 or Pt). The C 60/Pt film upon laser ablation produces the ions [C 58Pt] - and [C 56Pt] -, which result from the substitution of a platinum atom for two carbon atoms, and [C 57Pt 2] -, which incorporates two platinum atoms into the cage. The C 60/Ir(CO) 2 film produces a different series of products, [C 59Ir] -, [C 58Ir] -, [C 57Ir] -, and [C 56Ir] -, in which an iridium atom can replace one or two carbon atoms within the fullerene cage. Studies of the structures of [C 58M] - by density functional theory (DFT) show that the isomer with the metal atom replacing the C 2 unit at a 6:6 ring junction of the fullerene is more stable than the less symmetrical isomer with the metal replacing a C 2 unit at a 5:6 ring junction. Evidence for the ability of the metal atoms in some of these fullerenes to bind added ligands has been obtained by conducting the laser ablation studies in the presence of 2-butene, where adducts such as [C 29Ir(2-butene)] -, [C 58Ir(2-butene)] -, [C 57Ir(2-butene)] -, and [C 56Ir(2-butene)] - have been observed. DFT calculations were also carried out to analyze the reactivity of [C 58Pt] - and [C 58Ir] - with ethylene as a model for 2-butene. The formation energy of [C 58Ir(C 2H 4)] - from [C 58M] - and C 2H 4 was computed to be -15.8 kcal mol -1.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry