Small Molecule Activation Chemistry of Cu-Fe Heterobimetallic Complexes Toward CS2 and N2O

In this contribution, we report the reactivity of polar, unsupported Cu-Fe bonds toward small-molecule heteroallenes. Insertion of CS2 into the polar Cu-Fe bond of (IMes)Cu-FeCp(CO)(2) proceeds at mild conditions and results in the simultaneous presence of two unprecedented CS2 binding modes (mu(3):eta(4) and mu(3):eta(3)) in the same product. Reactivity between N2O and (NHC)Cu-FeCp(CO)(2) complexes also is observed at mild conditions, resulting in migration of the cyclopentadienyl groups from Fe to Cu. Similar reactivity is observed for new (NHC)Cu-FeCp*(CO)(2) analogues, whose structural characterization is reported here and reveals two semibridging Cu center dot center dot center dot Co interactions per molecule. Stoichiometric oxygen atom transfer from N2O to PPh3 was mediated by (IMes)Cu-FeCp(CO)(2), indicating the presence of an N2O-activated intermediate that can be intercepted by exogenous reagents.