Abstract
The gasโphase chemistry of Fe(C~6~H~4~)~n~^+^ (n = 1โ6) with C~60~ is studied by using Fourier transform ion cyclotron resonance mass spectrometry. The formation of some ionic phenylene derivatives and metallacyclic derivatives of C~60~ is observed. Specifically, Fe^+^, generated by laser desorption, reacts with chlorobenzene to form ironโbenzyne, FeC~6~H~4~^+^, which initiates further reactions with chlorobenzene to form Fe(C~6~H~4~) and (C~6~H~4~). Fe(C~6~H~4~) react with C~60~ to form metalated fullerene derivatives, C~60~Fe(C~6~H~4~). C~60~Fe(C~6~H~4~) undergo a demetalation reaction with chlorobenzene to yield the fullerene phenylene derivatives C~60~(C~6~H~4~), 8 and 9, through formation of C๏ฃฟC bonds with C~60~. CID experiments and kinetic analysis indicate that each of the C~60~Fe(C~6~H~4~) species consists of a single isomer, presumably the metallacycles 12 and 14. Consistent with the typical reactions of metalโbenzyne complexes with alkenes in the condensed phase, these metallacyclic structures are believed to be formed through coupling of one of the double bonds at the 6,6 ring junction in C~60~ with an Fe๏ฃฟC ฯ bond of Fe(benzyne)^+^. These results are consistent with the notion that C~60~ acts like an electron deficient alkene rather than an aromatic molecule, and suggest a possible synthetic route to prepare this type of metalloโC~60~ derivatives in the condensed phase. Finally, ligand displacement reactions yield a bond dissociation energy of Dยฐ(Fe^+^๏ฃฟC~60~) = 44 ยฑ 7 kcal/mol.