Activation of multiple C-H bonds promoted by gold in AuNbO(3)(+) clusters.

Single, double, triple: Highly selective double H atom abstraction (HAA) from ethane and triple HAA from n-butane by AuNbO(3)(+) clusters have been characterized by mass spectrometry and DFT calculations. The multiple HAAs are initiated by oxygen-centered radicals and promoted by gold. The gold atoms act as electron acceptors during the triple HAAs and help to store a pair of valence electrons between Au and Nb atoms.