Crossing the oxo wall

CHED 1486

Harry B. Gray, Beckman Institute, California Insitute of Technology, Pasadena, CA 91125
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. For several years I have pointed out that this powerful pi donor property places an “oxo wall” between Fe-Ru-Os and Co-Rh-Ir in the periodic table. You dare not claim that there is a stable metal-oxo complex in a tetragonal ligand field beyond the wall! This bold assertion stimulates much discussion in courses in which electronic structural concepts are taught. I will challenge the distinguished Pimentel awardee, my good friend Dick Zare, to come up with an oxo complex that is on the wrong side of the oxo wall.