Synthesis, structure and theoretical studies of Hg(II)-NH carbene complex of annulated ligand pyridinyl[1,2-a]{2-pyridylimidazol}-3-ylidene hexaflurophosphate

► Annulated N-heterocyclic carbenes offer robust Hg-complexes. ► Syn-conformers are more stable than its anti-isomers proved by B3LYP/LANL2DZ energy calculation. ► Hg-NHC enables in transmercuration/orthomercuration reaction. ► Non-coordinated pyridine nitrogen center can bind hard electrophile leading to bimetallic system.