Coupling reactions of Fe(benzyne)+ and Fe(naphthyne)+ in the gas phase

The gas phase ion-molecule reactions of Fe(benzyne) + and Fe(naphthyne) + with acetylene, allene, ethene, butadiene, buckminsterfullerene and cyclopropane are studied using Fourier transform ion cyclotron resonance mass spectrometry. In a previous study we proposed that the reaction of Fe(benzyne) + with ethene proceeds by a mechanism in which a multiple carbon-carbon bond couples with a metal-carbon bond of Fe(benzyne) + to form new carbon-carbon and metal-carbon bonds. In this study we include the reactions of Fe(naphthyne) + in order to test the generality of this mechanism and to observe the non-metallic products formed in these reactions. Fe(benzyne) + , for example, reacts with acetylene to yield Fe + and C e H,CH, exclusively. In contrast the reaction of Fe(naphthyne)+ with acetylene produces Fe + , C 10 H 6 C 2 H 2 + and a metallacyclic product Fe-C 10 H 6 -CH 2 H 2 + . This lends support that the neutral product formed in the reaction of Fe(benzyne) + with acetylene is an intact C 6 H 4 C 2 H 2 . Similarly, Fe(naphthyne) + reacts with ethene to form a metallacyclic product Fe-C 10 H 6 -C 2 H 4 + . In the reaction with C 60 , Fe(naphthyne) + is observed to yield the C 60 derivatives C 60 C 10 H 6 + and Fe-C 10 H 6 -C 60 + . These gas phase ion-molecule coupling reactions are analogous to the condensed phase coupling reactions of metal-lobenzynes with molecules containing multiple bonds.