Stabilization of Sb Tetrahedra in Paramagnetic Transition Metal Carbonyl Complexes.

We present a straightforward synthetic route to the novel chromium carbonyl-stabilized paramagnetic Sb-based cluster [EtN][SbCr(CO)] ([EtN][]), which represented a rare example of the intact Sb tetrahedron structurally characterized in the solid state. Complex exhibited versatile reactivities toward groups 7-9 metal carbonyls, dioxygen, or [Cu(MeCN)][BF] to form selective orbital-controlled Sb-based products, including transmetalated paramagnetic complexes [EtN][SbCrMn(CO)]Br ([EtN][]Br), [EtN][SbCrFe(CO)] ([EtN][]), and [EtN][SbCrCo(CO)] ([EtN][]), the dioxygen-activated paramagnetic cluster [EtN][OSbCr(CO)] ([EtN][]), or the spin-quenched complex [EtN][SbCr(CO)] ([EtN][]), respectively. The structural nature, bonding properties, paramagnetism, and semiconductivity of these unprecedented transition metal carbonyl-protected Sb-based clusters were further realized with DFT calculations.