Understanding\nthe Role of NHC Ditopic Ligand Substituents\nin the Molecular Diversity and Emissive Properties of Silver Complexes

Silver bis(carbene) complexes featuring ditopic N-heterocyclic\ncarbene (NHC) ligands have been synthesized which enable the assembly\nof supramolecular architectures via reaction with silver triflate.\nThrough a systematic exploration of crystal structures and emissive\nproperties, this study investigates the impact of the substituents\non the NHC ditopic ligands [R-Im-2-Z-py], where R = Me, benzyl (Bz),\nor 2-naphthylmethyl (NaphCH<sub>2</sub>), and Z = H or Cl in the structural\nframework and emissive properties observed in the silver bis(carbene)\nor polynuclear species. Remarkably diverse structural motifs emerge\nin both of them, predominantly influenced by the choice of R wingtip\nand second by the Z substituent. Also the emissive quantum yield of\nthe complexes is mostly governed by the selection of the R wingtip\nand further modulated by the Z substituent. Several of the mono and\npolynuclear complexes exhibit complex emissive profiles, including\nthe observation of dual emission phenomena. Particularly noteworthy\nis the complex [Ag(NHC)]<sub>2</sub>]OTf (R = Bz, Z = Cl), which demonstrates\nan exceptionally intense single blue emission with a remarkable solid-state\nquantum yield (Φ) of 24%.