Carbenes in a Supersonic Jet Expansion

Hydrogen Bond (HB) is one of the important intermolecular forces and is ubiquitous in Chemistry and Biology. Since it has strong directional nature it plays an important role in supramolecular chemistry as well as molecular recognition. These H-bonds play a vital role in determining the structure of proteins and supramolecules and there is evidence of these interactions in literature.
 
Among different reactive intermediates, Carbene being neutral and highly electron-deficient species play a significant role in various organic transformations. Hydrogen bonding that involves carbene as a hydrogen acceptor is very poorly documented in the literature.¹

For instance, N-heterocyclic carbene carbon (singlet ground state) is highly nucleophilic due to adjacent nitrogen centres. Such electron-rich nucleophilic species can act as powerful Lewis bases. Water, being proton donor, can interact with Lewis bases like nucleophilic carbenes to form the strong hydrogen-bonded complex.