A Trinuclear Silver(I) Functionalized N-Heterocyclic Carbene Complex and Its Use in Transmetalation: Structure and Catalytic Activity for Olefin Polymerization^†

Deprotonation of an imidazolium salt with silver oxide forms the silver carbene complex {[Ag(C∧N)2]3I}I2 (2; C∧N = 3-methyl-1-picolylimidazolin-2-ylidene). The Ag−carbene complex undergoes a facile reaction with Pd(PhCN)2Cl2 to yield the carbene complex Pd(C∧N)Cl2 (3). Complexes 2 and 3 have been characterized by IR, 1H and 13C NMR spectra, and elemental analyses. The molecular structures of complexes 2 and 3 have been confirmed by X-ray single-crystal analyses. Complex 2 shows moderate catalytic activities of up to 105 g of PE (mol of Ag)-1 h-1 for ethylene polymerization, and complex 3 shows very high catalytic activities of up to 108 g of PNB (mol of Pd)-1 h-1 for the addition polymerization of norbornene in the presence of methylaluminoxane (MAO) as cocatalyst.