According to the reaction of [Fe(CO)(2)C5H5](2) with sodium amalgam(Na/Hg), the molecular structures of crystals and the IR data of L3SnFe (CO)(2)C5H5 (L=C6H11, C6H5), [(C5Me5)(2)Ln(CO)(2)FeC5H5](2) (Ln=Dy, Gd, Sm, Nd, Pr) complexes, the process of forma tion of (Na[Fe(CO)(2)C5H5](2))(n), its structure changes and reaction regularities in the syntheses of heteronuclear metal complexes were analyzed and discussed.