Synthesis of solvento-complexes by metal oxidation in non-aqueous solvents

2 Synthesis of solvento-complexes by metal oxidation in non-aqueous solvents 

In order to prepare a homoleptic solvento-complex by metal oxidation in a non-aqueous medium, the reduction products must not compete with the solvent molecules as ligands. Nitrosonium perchlorate, N(DC104, is a suitable oxidant. 4,15 Reactions have been performed in acetonitrile, nitromethane and ethylacetate. In acetonitrile this oxidant converts copper powder into the copper(I) and copper(II) homoleptic solvento-complexes, [Cu(MeCN)4][C104] and [Cu(MeCN)4][C104]2. On boiling an acetonitrile solution of these complexes with metallic copper, reduction of the copper(II) 

Silver salts containing anions of strong adds are suitable reagents for synthesis of solvento-complexes by metal oxidation in non-aqueous solvents. Metallic gold in acetonitrile reacts with silver perchlorate to produce [Au(MeCN)4][C104], Eq. 4.3  

The synthesis of [Cu(MeCN)4][N03] was accomplished in a similar manner l with AgNOs. The liberated silver was separated easily from the reaction mixture. 

The complexes, [Fe(py 4]X2 (X = Br, 1), have been prepared by oxidation of metallic iron with bromine or iodine in methanol. Pyridine is added to the resultant solution and the pyridine complexes precipitated.22 Interaction between metallic zinc or cadmium and an excess of arsenic pentafluoride in liquid sulfur dioxide leads to the formation of solvento-complexes containing two or four SO2 ligands depending on the experimental conditions.23/24 The reactions studied are summarized as follows, Eq.4.4  

---