Iron-carbonyl complex trigonal bipyramidal

The two isostructural complexes [Fe(CX))4(AsMes)] and [Fe(CO)4(SbMe3)l also contain iron atoms in trigonal-bipyramidal co-ordination, with the equatorial sites occupied by three carbonyl groups. The respective Fe-As and Fe-Sb distances are 2.30(3) and 2.49(2) A. The [Fe(CO)4(QFs-As -CgFs)] molecule (7) has symmetry, and the iron atom is in a distorted... 

Some iron and nickel cyanide and carbonyl complexes have been reported as models of the [FeNi]-hydrogenase enzymes. The preparation and structures of the trigonal bipyramidal nickel and iron complexes with the tetradentate ligands tris(2-phenylthiol)phosphine (PS3) and tris(3-phenyl-2-thiophenyl)phosphine (PS3 ) have been reported [70, 71]. The nickel carbonyl complex [Ni(PS3 )(CO)] exhibits vco at 2029 cm compared with the value of 1940 em" for the iron earbonyl complex [Fe(PS3 )(CO)]. Both of these complexes lose CO upon oxidation. The use of cyanide in place of carbon monoxide allows for the preparation of both [Fe (PS3)(CN)] and [Fe (PS3 )(CN)] eomplexes. The IR properties of... 

A.iii. Sodium Tetracarbonyl Ferrate. An extremely useful organoiron reagent is sodium tetra-carbonyl ferrate [Na2Fe(CO)4], usually prepared by reduction of iron pentacarbonyl. The synthetic utility of this reagent lies in its ability to react with alkyl halides in a stepwise manner, including the reaction with two different alkyl halides, as reported independently by Cooke and by Collman and co-workers. - When sodium tetracarbonyl ferrate reacted with 1-bromooctane, a trigonal bipyramidal complex (715) was formed... 

The first mononuclear carbonyl compound of cobalt, iron or manganese known was the pentacarbonyl complex [Fe(CO)5] " with a trigonal-bipyramidal ligand field (see Fig. 2). Though related electroneutral species of cobalt and manganese are not known due to a strict observance of the 18-electron-rule in these cases, the monoanionic manganese derivative fMn(CO)5] has also been described as a trigonal-bipyramidal species. ... 

Metal complexes have a variety of stractures. Silver complexes are often linear beryllium complexes are usually tetrahedral iron forms a carbonyl compound that has a trigonal bipyramidal structure cobalt(lll) complexes are octahedral and tantalum forms an eight-coordinated fluoride complex (Figure 3.1). Although a variety of coordination numbers and structures have been observed in metal complexes, the only common coordination numbers are four and six the common structures corresponding to these coordination numbers are tetrahedral and square planar, and octahedral, respectively. In studying metal complexes, it soon becomes clear that the octahedral structure is by far the most common of these configurations. 

---