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

Abstract

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 (μ3:η(4) and μ3:η(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···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.