Molecular and Ionic Hydrogen Isocyanide (CNH) Adducts with N‐H…O‐ and “Super‐Short” N‐H…N‐Hydrogen Bridges: Metal‐Stabilized Hydrogen Bisisocyanides

Abstract

The metal-coordinated hydrogen isocyanide in [Cr(CO)5CNH] proved to be an ideal hydrogen-bond former. Its discrete adducts with ethers and cyano complexes are surprisingly stable and some are sublimable (1, [Cr] = Cr(CO)5). According to IR, X-ray structure, and 15NMR investigations, strong N-H…︁O hydrogen bonds are present. The shortest bonds are found for 2 ([Fe] = FeCp(diphos)) and 3. In 3, the N-H…︁N bonds are symmetrical. diphos = bis(diphenylphosphino)ethane.