Synthesis, Characterization, and Electronic Properties of Porphyrins Conjugated with N‑Heterocyclic Carbene (NHC)–Gold(I) Complexes

Porphyrins
fused to peripheral N-heterocyclic carbenes (NHC) across
two neighboring β,β-pyrrolic positions were used for the
synthesis of different mono- and bis-carbenic gold­(I) complexes. These
studies also revealed how it is possible to modulate the reactivity
of the peripheral NHC by deprotonating the inner NH groups of the
fused free base porphyrin core. All complexes were fully characterized
and displayed high stability, allowing the formation of mono-carbenic
and also stable homoleptic and heteroleptic bis-carbenic Au­(I) complexes.
Optical and electrochemical properties of bis-carbenic Au­(I) revealed
no or weak electronic communication between the porphyrins, which
behave as two independent groups.