Ligand-Directed Metalation of a Gold Pyrazolate Cluster

[Image: see text] Solid “[AuL]” (HL = 3-[pyrid-2-yl]-5-tertbutyl-1H-pyrazole) can be crystallized as cyclic [Au(3)(μ-L)(3)] and [Au(4)(μ-L)(4)] clusters from different solvents. The crystalline tetramer contains a square Au(4) core with an HT:TH:TH:HT arrangement of ligand substituents, which preorganizes the cluster to chelate to additional metal ions via its pendant pyridyl groups. The addition of 0.5 equiv of AgBF(4) to [AuL] yields [Ag(2)Au(4)(μ(3)-L)(4)][BF(4)](2), where two edges of the Au(4) square are spanned by Ag(+) ions via metallophilic Ag···Au contacts. Treatment of [AuL] with [Cu(NCMe)(4)]PF(6) affords the metalloligand helicate [Cu(2)Au(2)(μ-L)(4)][PF(6)](2), via oxidation of the copper and partial fragmentation of the cluster.