Hydrazine Capture and N-N Bond Cleavage at Iron Enabled by Flexible Appended Lewis Acids.

Incorporation of two 9-borabicyclo[3.3.1]nonyl substituents within the secondary coordination sphere of a pincer-based Fe(II) complex provides Lewis acidic sites capable of binding 1 or 2 equiv of N2H4. Reduction of the 1:1 Fe:N2H4 species affords a rare Fe(NH2)2 complex in which the amido ligands are stabilized through interactions with the appended boranes. The NH2 units can be released as NH3 upon protonation and exchanged with exogenous N2H4.