Photolysis-driven bond activation by thorium and uranium tetraosmate polyhydride complexes

Abstract

Transition metal multimetallic complexes have seen intense study due to their unique bonding and potential for cooperative reactivity, but actinide–transition metal (An–TM) species are far less understood. We have synthesized uranium– and thorium–osmium heterometallic polyhydride complexes in order to study An–Os bonding and investigate the reactivity of An–Os interactions. Computational studies suggest the presence of a significant bonding interaction between the actinide center and the four coordinated osmium centers supported by bridging hydrides. Upon photolysis, these complexes undergo intramolecular C–H activation with the formation of an Os–Os bond, while the thorium complex may activate an additional C–H bond of the benzene solvent, resulting in a μ-η¹,η¹ phenyl ligand across one Th–Os interaction.