Iron complexes carbonyl tellurides

Other complex iron carbonyl tellurides can be obtained by solvothermal reactions. Compound 53, (Me4N)2[Fe4(Te2)2(Te)2(TeMe)2(CO)g], is produced when Fe3(CO)i2, Na2Te2, and Me4NBr are mixed with a small amount of methanol and heated at 110°C. This complex exhibits solvent-derived methylation of Te ions, which was not expected. 

On the other hand, polytellurides only seem to oxidize metals to the +1 or +11 state. Reaction of equimolar amounts of Te4 with M(CO)6 results in disubstitution of CO forming a cu-complex (CO)4MTe4 (M = Cr (45), W (47)47). If an excess of metal carbonyl is used in the presence of poly-telluride anion, multinuclear products can be isolated and metal-metal bonds can also form, leading to clusters. Careful manipulation of reaction conditions and choice of the polychalcogenide anion used makes possible partial oxidation of the metal centers and cluster formation. The reaction of iron carbonyls with polytelluride anions can lead to a wide array of cluster compounds, the identities of which are controlled by the stoichiometries and compositions of the starting telluride anions. For instance, reaction of [Fe(CO)5] with Te2 leads to the formation of [Fe3(CO)9(ju.3-Te)]2 (48),48 whereas its reaction with increasing amounts... 

The reactions of iron carbonyls with diorgano tellurides deserve mention, for example the reaction of Fe3(CO),2 with PhjTe gives Ph2TeFe(CO>4, whilst several ruthenium-carbonyl complexes have been prepared from reactions between diphenyl telluride and alcoholic carbon monoxide-saturated solutions of ruthenium trichloride hydrate. Various other ruthenium-carbonyl complexes of diorgano teUurides, including di- and tri-substituted species, have also been described. The utility of diphenyl telluride in transition metal carbonyl chemistry has also been well illustrated during studies of manganese and rhenium compounds. 

Similar to reactions with arsenic selenide anions described in the previous section, pentacarbonyliron or the hydrido-iron tetracarbonyl anion react with arsenic tellurides to produce complex iron carbonyl-bound tellurium arsenic anions (Scheme 85). Unlike the selenium analogs, the isolated complex for Te does not exhibit Fe-As bonds. 

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