Ligand substitution reactions iron

Ligand Substitution Reactions of ij Heptafluorocyclooctatetraenyl Complexes of Iron... 

Figure 2 Electron transfer series in native and synthetic model clusters of the Fe4S4 center in the Fe-protein. Redox potential versus NHE, Fe Mossbauer isomer shift (S at 4.2 K vs. iron), mean iron oxidation state, and spin state are indicated for each redox state. Syntheses and ligand-substitution reactions are indicated for synthetic clusters...

Starting with [PtCU] , you need to perform two separate ligand substitution reactions. In one, NH3 will replace Cl" ion. In the other, NOi" ion will replace Cl" ion. The question is which substitution to perform first. According to the trans effect series shown in Section 21.4, the strength of the irons effect for die three ligands in question is... 

Peroxo-diiron(III) complexes can undergo not only redox but also ligand substitution reactions. Liberation of H202 was observed in the reactions with phenols and carboxylic acids leading also to the respective phenolate or carboxylate iron(III) complexes.86 Hydrolysis of a peroxo-diiron(III) complex results in an oxo-diiron(III) species and hydrogen peroxide. Such reaction is responsible for the autoxidation of hemerythrin, but is very slow for the native protein due to hydrophobic shielding of the active site (Section 4.2.3).20 The hydrolysis of iron(III) peroxides is reversible, and the reverse reaction, the formation of peroxo intermediates from H202 and the (di)iron(III), is often referred to as peroxide shunt and is much better studied for model complexes. 

Generalized ligand substitution reaction (24) proceeds with a variety of anionic ligands such as halides, thiolates, and arene oxides. Certain neutral ligands also substitute on the 6484] core, notably isonitriles and tertiary phosphines. Although nitrosyl clusters are not within the purview of this section, we note the existence of cubane-type [Fe4S4(NO)4] . Iron-sulfur-nitrosyl... 

Figure 5.15 [Fe(pyrimidine) H20)(M(CN)2)2] H,0, M=Ag, Au is an example of the cds (CdS04) net. The Ag compound is show with iron-centred nodes and Ag ions are shown as nicks on the links. This structure is triply interpenetrated and the compound exhibits spin crossover with hysteresis and dramatic colour change as well as a solid-state ligand substitution reaction with loss of water, making the pyrimidine ligand bridging irons from two different nets [33].

Ligand substitution reactions of the iron-group trimetal dodecacarbonyl clusters and derivatives from them have been extensively studied. M3(CO)i2 cluster, as it frequently occurs with stable small tri and tetranuclear clusters, is constituted by saturated 18-electron metal atoms. Accordingly dissociative pathways for substitutions in these compounds are expected. 

Two of the papers presented at the Fifth International Conference on Non-aqueous Solvents are of direct relevance to this Report. They deal with solvent effects on kinetics, in the areas of ligand substitution reactions at labile centres, and of preferential solvation in such systems." Another review on preferential solvation and its consequences deals primarily with chromium(iii) complexes, such as the [Cr(NCS)6] anion, in binary aqueous mixtures, but also mentions other groups of inorganic substrates such as low-spin iron(ii) complexes. A short article on the effectiveness of a solvent in catalysis considers such topics as affinities for nf-electrons and polarization potentials. ... 

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