Reactions between M + (M = Si, Ge, Sn and Pb) and benzene in the gas phase

Using a laser ablation/inert buffer gas ion source coupled with a reflectron time‐of‐flight mass spectrometer, the gas‐phase reactions between the IVA group element ions M + (M = Si, Ge, Sn and Pb) and benzene seeded in argon gas were studied. In addition to the association reaction pathway (forming [M(C 6 H 6 ) x ] + , x = 1, 2, etc.), benzene was dissociated to form complex ions [M(C 5 H 5 )] + , [M(C 7 H 5 )] + and [M(C 9 H x )] + (x = 5, 7 and 9), etc. DFT theoretical calculations indicated that, in the association products [M(C 6 H 6 )] + , the M atom is close to one carbon atom of benzene, while in most of the dissociation complexes, pentagonal structures (M/cyclopentadienyl derivatives) were formed, with the M atom situated near the fivefold axis of the five‐membered ring. The bond patterns in these complexes are discussed. Copyright © 2003 John Wiley & Sons, Ltd.