Defining the Electronic Structure of Transition Metal Singlet Dioxygen Adducts
Rhodium(I) complexes generally bind dioxygen through oxidative addition to form stable Rh(III) peroxo complexes. In collaboration with Cathy Crudden at Queen's University, we recently reported a series of stable square planar Rh(I) complexes which behave very differently in the presence of dioxygen - the products of oxygenation remain square planar and O2 binds side-on while keeping a very short O-O bond distance. Using a combination of computational and spectroscopic methods, we have determined that these represent a previously undiscovered class of metal dioxygen complexes: singlet dioxygen adducts. we are presently exploring the nature of the bonding in these species and determining its impact on reactivity.
See Praetorius et al, JACS 2008; Cipot-Weshler et al, Organomet 2012; and Keske et al, Dalton Trans 2013 for more details.