Exploring The Role Of Carbonate In The Formation Of An Organomanganese Tetramer

The formation of metal oxygen clusters is an important chemical transformation in biology and catalysis. For example, the biosynthesis of the oxygen evolving complex in the enzyme photosystem II is a complicated stepwise process that assembles a catalytically active cluster. Herein we describe the role that carbonato ligands have in the formation of the known tetrameric complex [Mn(CO)(3)(mu(3)-OH)](4) (1). Complex 1 is synthesized in one step via the treatment of Mn-2(CO)10 with excess Me3NO center dot 2H(2)O. Alternatively, when anhydrous Me3NO is used, an OH-free synthetic intermediate (2) with carbonato ligands is produced. Complex 2 produces carbon dioxide, Me3NO center dot 2H(2)O, and 1 when treated with water. Labeling studies reveal that the mu(3)-OH ligands in 1 are derived from the water and possibly the carbonato ligands in 2.