Metal—ligand bonds hydrogen sulfide

Kubas discovered reactions of the Cp dimers, which are part of a catalytic cycle for the hydrogenation of SO2 (equation 26). The net reactions involve the coordinated sulfur and may or may not involve the metal atoms, which may be the true spectators in this chemistry. This opens the possibility that the metal-metal bond serves to stabilize the reacting fragment without direct involvement in the chemistry. However, reaction could also occur at the metal-metal bond followed by transfer to the sulfide ligands. These types of multiple interactions give an added dimension, but also an added complexity, to metal-metal bonded chemistry with bridging functional ligands. 

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