Structure and Gas-Phase Thermochemistry of a Pd/Cu Complex: Studies on a Model for Transmetalation Transition States

A heterobimetallic Pd­(II)/Cu­(I) complex was prepared and characterized by X-ray diffraction analysis. The crystal structure shows a remarkably short Pd–Cu bond and a trigonal ipso carbon atom. The Pd–Cu interaction, as determined by energy-resolved collision-induced dissociation cross-section experiments, models the net stabilizing energy of the Pd–Cu interaction in the transition state of the transmetalation step in Pd/Cu-catalyzed cross-coupling reactions. The bonding situation in the bimetallic dinuclear complex has been studied by atoms-in-molecules analysis.