Reductive Coupling of Azides Mediated by an Iron(II) Bis(alkoxide) Complex

The iron(III) hexazene complex (RO)(2)Fe(mu-kappa(2):kappa(2)-AdN(6)Ad)Fe(OR)(2) (3) was synthesized via reductive coupling of 1-azidoadamantane at the iron(II) bis(alkoxide) complex Fe(OR)(2)(THF)(2) (2). The X-ray crystal structure depicts electron delocalization within the hexazene moiety. Density functional theory studies propose the formation of an iron azide dimer on the route to hexazene, in which each azide is monoreduced and the iron centers are oxidized to the 3+ oxidation state.