Group 11 complexes of a bulky triazene ligand

Abstract

A new triazene ligand was prepared by the reaction of the bulky aryl azide, TerMesN₃, (2,6-bis(2,4,6-trimethylphenyl)phenyl azide), with the bulky N-heterocyclic carbene (NHC), SIPr (N,N′-2,6-bis(diisopropylphenyl)-3,4-dihydroimidazol-2-ylidene). The steric bulk of these two groups leads to perpendicular bonding of the NHC-N₃ plane and the aryl group which provides immense steric crowding around the triazene core. The corresponding π-conjugated triazene ligand was utilized as a neutral, monodentate ligand which results in monomeric Cu(I)Cl, Ag(I)OTf, and Au(I)Cl complexes. Instability of the π-conjugated triazene Au(I)Cl complex was observed, even under inert conditions. When dissolved and photolyzed in THF with workup in isopropanol, the compound decomposes forming [(SIPrNH)₂Au(I)][Au(I)Cl₂] a relatively stable compound to light, moisture, and water – alongside the formation of gold nanoparticles which were characterized using scanning electron microscopy with energy dispersive spectroscopy.