Solution and Gas-Phase Reactivity of Me Fe and Related Cluster Ions.

The cluster ion Me Fe is an unprecedented representative of organoiron species, which are of great interest because of their possible role as intermediates in iron-catalyzed cross-coupling reactions. To learn more about its behavior in solution, the possible formation of related cluster ions, and their reactivity, electrospray-ionization mass spectrometry and gas-phase experiments were performed. Me Fe adopts a highly dynamic behavior in solution and disappears in the presence of the chelating ligand N,N,N',N'-tetramethylethylenediamine. Besides homoleptic Me Fe , its heteroleptic analogues Me Fe Ph , n=1-5, are also accessible. Me Fe undergoes iron-halogen exchange reactions with aryl halides. These substrates, as well as their alkyl counterparts, mediate the formation of new homoleptic cluster ions up to Me Fe . In contrast, no evidence was found for oxidative additions or related reactions. Gas-phase fragmentation of the cluster ions results in numerous different reactions, ranging from the loss of single methyl radicals to the reductive elimination of MePh.