Life Depends on Metal Oxos
Presented by Prof. Harry Gray
Hosted by Prof. Parkin
Abstract:
The dianionic oxo ligand occupies a very special place in coordination chemistry, owing to its ability to donate pi electrons to stabilize high oxidation states of metals. The ligand field theory of multiple bonding in metal oxos predicts that there must be an oxo wall between Fe-Ru-Os and Co-Rh-Ir in the periodic table. Iron and manganese oxos, which are on the allowed side of the wall, play key roles in three of the most important chemical reactions on planet Earth: water oxidation to oxygen catalyzed by a MnCa cluster in photosystem II; oxygen reduction to water catalyzed by cytochrome oxidase, the terminal enzyme in respiration; and hydrocarbon oxygenation to alcohols catalyzed by cytochrome P450. In my lecture, I will address the following question: When high potential P450 iron-oxos fail to oxygenate substrates, how is the enzyme protected from oxidative degradation?
