THE SUPERBULKY P-n LIGAND COMPLEXES [(CpFe)-Fe-BIG(eta(5)-P-5)] AND [((CpFe)-Fe-BIG)(2)(mu,eta(4:4)-P-4)]-SYNTHESIS AND CHARACTERIZATION

A new synthesis of [(CpFe)-Fe-BIG(CO)(2)](2) 3 (Cp-BIG = C-5(4-(BuC6H4)-Bu-n)(5)) was developed starting from (CpNa)-Na-BIG and FeCl2 in the presence of CO. Reaction of this product with P-4 leads to the two new P-n ligand complexes [(CpFe)-Fe-BIG(eta(5)-P-5)] 1b and [((CpFe)-Fe-BIG)(2)(mu,eta(4:4)-P-4)] (4) containing the highly sterically demanding Cp-BIG ligand. Depending on the solvent, different ratios of 1b: 4 are obtained. The products 1b, 3, and 4 were characterized by spectroscopic methods as well as by X-ray diffraction.