Hydridocarbonyls and Their Derivatives

The synthesis of [Fe4(CO)i3]2- (structure in Fig. 10) has been extensively studied by Hieber and co-workers. The reaction of a variety of ligands with Fe(CO)5 results in redox condensation reactions and formation of the dark red dianion [Fe4(CO)i3]2 

The formation of [Fe4(CO)i3]2 in these systems involves a complicated series of reactions but the final condensation step is possibly related to the following reaction127  

The same dianion has been obtained in 90% yield using Cr(7 6-Ph-Ph)2 as a reducing agent 

The related monoanion [Fe3Co(CO)13] has been obtained [Eq. (10)] although it has not yet been completely characterized61.  

Two isomers of this compound (designated a and 0) have been claimed (see Table 10) although most preparations usually give the a-isomer which has the structure shown in Fig. 9. The osmium dihydride, Os4(CO)13H2, which is probably iso-structural with a-Ru4(CO)i3H2, has been obtained from the mixture resulting on pyrolysis 

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