A novel N-heterocyclic carbene 1,3-alternate calix[4]arene
complex
bearing four palladium(II) centers per ligand has been prepared. Electrochemical
synthetic methods were used to prepare the corresponding copper(I)
complex, followed by transmetalation onto palladium(II). The activity
of the palladium complex was probed in the Suzuki–Miyaura cross-coupling
reaction. An inverse correlation between palladium concentration and
activity was observed, with the results indicating that calix[4]arenes
in the cone conformation may reduce the aggregation of palladium(0)
nanoclusters, whereas our 1,3-alternate calix[4]arene does not provide
any supramolecular stabilizing effect.