Reactions of In–Zn Bonds with Organic Azides: Products that Result from Hetero- and Homo-bimetallic Behaviour

The indyl anion, K[In(NONDipp)] (NONDipp = [O(SiMe2NDipp)2]2–, Dipp = 2,6-iPr2C6H3) reacts with group 12 compounds M(BDIR)Cl (M = Zn, Cd; BDI = [HC{C(Me)NR}2]–, R = 2,4,6-Me3C6H2 (Mes), Dipp) to afford the heterobimetallic compounds (NONDipp)In–M(BDIR) that contain the first In–Zn and In–Cd bonds. The reactivity of the In–Zn bonds towards organic azides, R'N3 (R' = Mes, Dipp, Ph) was investigated. (NONDipp)In–Zn(BDIMes) reduces MesN3 via an isolable triazenide intermediate to generate the bridging imido compound, (NONDipp)In-(μ-NMes)-Zn(BDIMes). Similar reactivity is noted from early-late heterobimetallic complexes. Under the same conditions, PhN3 reacts to afford a product that contains a bridging tetraazenide ligand, which is formed from the formal (2+3)-cycloaddition of second azide to an indium-imido bond. However, increasing the bulk of the BDI-ligand in (NONDipp)In–Zn(BDIDipp) leads to reductive coupling of PhN3 to give the hexazene complex. This mode of reactivity is reminiscent of the reductive behaviour of homobimetallic compounds.