Novel main group-transition metal cluster compounds incorporating antimony, iron and cobalt

The reaction of [{Cp-x(CO)(2)Fe}SbCl2] [1a: Cp-x = eta (5)-C(5)H(3)tBu(2)-1 ,3 (Cp "); 1b: Cp-x = eta (5)-C5Me5 (Cp*)] with Na-2[Fe(CO)(4)] or K[Co(CO) (4)] affords the novel antimony-transition metal cluster compounds [{mu (3) -SbFe(CO)(2)Cp "}(3){Fe(CO)(3)}(4)] (2), [{Fe-3(CO)(9)}{mu (3)-SbFe(CO)(2)C p "}(2)] (3) and [{mu (4)-SbFe(CO)(2)-Cp*}(2)(Co-4(CO)(10)(mu -CO))] (4). A ll products were characterised by X-ray structure analyses and other method s. Cluster 2 reveals a novel Sb3Fe4 core, which does not follow the Wade-Mi ngos rules. Cluster 3 forms a square-pyramidal nido-cluster. The Sb2Co4 clu ster core of 4 derives from a pentagonal bipyramid and consists of apical S b and equatorial Co atoms with one missing pentagonal core atom.