Reactions of Mesityl Azide with Ferrocene-Based N-Heterocyclic Germylenes, Stannylenes and Plumbylenes, Including PPh -Functionalised Congeners.

The reactivity of ferrocene-based N-heterocyclic tetrylenes [{Fe(η -C H -NSitBuMe ) }E] (E=Ge, Sn, Pb) towards mesityl azide (MesN ) is compared with that of PPh -functionalised congeners exhibiting two possible reaction sites, namely the E and P atom. For E=Ge and Sn the reaction occurs at the E atom, leading to the formation of N and an E =NMes unit. The germanimines are sufficiently stable for isolation. The stannanimines furnish follow-up products, either by [2+3] cycloaddition with MesN or, in the PPh -substituted case, by NMes transfer from the Sn to the P atom. Whereas [{Fe(η -C H -NSitBuMe ) }Pb] and other diaminoplumbylenes studied are inert even under forcing conditions, the PPh -substituted congener forms an addition product with MesN , thus showing a behaviour similar to that of frustrated Lewis pairs. The germylenes of this study afford copper(I) complexes with CuCl, including the first structurally characterised linear dicoordinate halogenido complex [CuX(L)] with a heavier tetrylene ligand L.