Transfer of polyantimony units

Transfer reagents are useful tools in chemistry to access metastable compounds. The reaction of [Cp′′(2)ZrCl(2)] with KSb(SiMe(3))(2) leads to the formation of the novel polyantimony triple decker complex [(Cp′′Zr)(2)(μ,η(1:1:1:1:1:1)-Sb(6))] (1, Cp′′ = 1,3-di-tertbutyl-cyclopentadienyl), containing a chair-like Sb(6)(6−) ligand. Compound 1 represents a valuable transfer reagent to form novel antimony ligand complexes. Thus, the reaction of 1 with Cp(R)-substituted transition metal halides of nickel, cobalt and iron leads to the formation of a variety of novel Sb(n) ligand complexes, such as the cubane-like compounds [(Cp′′′Ni)(4)(μ(3)-Sb)(4)] (2) and [(Cp′′′Co)(4)(μ(3)-Sb(4))] (3a) or the complexes [(Cp(Bn)Co)(3)(μ(3)-Sb)(2)] (4) and [(Cp′′′Fe)(3)(μ(3)-Sb)(2)] (5), representing a trigonal bipyramidal structure. Moreover, beside the transfer of Sb(1) units, also the complete entity can be transferred as seen in the iron complex [(Cp′′′Fe)(3)(μ(3,)η(4:4:4)-Sb(6))] (6). DFT calculations shed light on the bonding situation of the products.