Alternative synthetic route for the heterometallic CO-releasing [Sb@Rh12(CO)27]3− icosahedral carbonyl cluster and synthesis of its new unsaturated [Sb@Rh12(CO)24]4− and dimeric [{Sb@Rh12Sb(CO)25}2Rh(CO)2PPh3]7− derivatives

The alternative high-yield synthesis for the previously known [Sb@Rh12(CO)27]3− icosahedral carbonyl cluster, in much milder reaction conditions, allowed us to carry out some chemical reactivity which led to the isolation and characterization of two new heterometallic Rh carbonyl clusters, namely [Sb@Rh12(CO)24]4− and [{Sb@Rh12Sb(CO)25}2Rh(CO)2PPh3]7−. We herein report their syntheses and full X-ray crystal structures, along with 31P NMR analysis of the latter compound.