Tetraimido Sulfuric Acid H 2 S(NtBu) 4 -Valence Isoelectronic to H 2 SO 4

The valence isoelectronic imido analog H S(NtBu) (1) of sulfuric acid H SO was synthesized, isolated, and characterized by NMR spectroscopy and high-resolution X-ray charge density analysis. The latter reveals strongly polarized S -N bonds with virtually no double bond character. The easy-to-polarize S-N bonds are an advantageous and versatile feature of sulfur nitrogen ligands, which enables them to adapt to different electron requirements of various metal cations.