Intramolecular Hydrogen Bonding Facilitates Electrocatalytic Reduction of Nitrite in Aqueous Solutions

The nitride ligand in the iron(IV) complex, PhB(MesIm)$_3$Fe N reacts with excess H$_3$SiPh to afford PhB(MesIm)$_3$Fe($\mu$-H)$_3$(SiHPh) as the major product, which has been structurally and spectroscopically characterized. The bulkier silane HaSiPh$_2$ provides the iron(II) amido complex PhB(MesIm)$_3$FeN(H)(SiHPh$_2$) as the initial product of the reaction, with excess H$_2$SiPh$_2$ affording diamagnetic PhB(MesIm)$_3$Fe($\mu$-H)$_3$(SiPh$_2$) as the major product. The unobserved iron(II) hydride PhB(MesIm)$_3$Fe-H is implicated as an intermediate in this reaction, as suggested by the results of the reaction between the iron(II) amido PhB(MesIm)$_3$FeN(H)tBu and H$_3$SiPh, which provides PhB(MesIm)$_3$Fe(H)($\mu$-H)$_2$(Si(NHtBu)Ph) as the sole product