Studies on some substituted methyl derivatives of iron, molybdenum, and tungsten

Abstract

The methoxymethyl complexes M–CH₂·OMe, where M =π-C₅H₅Fe(CO)₂ or π-C₅H₅(Mo or W)(CO)₃, have been prepared. It is shown that a methoxy-group is readily cleaved from the system by acids. Hydrogen chloride forms the chloromethyl complexes M–CH₂Cl which react readily with hydroxy-compounds ROH, forming the ether derivatives M–CH₂OR. Cleavage of the iron methoxymethyl complex with the acids H⁺A^–, where A = ClO₄, PF₆, or BF₄, gives a mixture of products which include the ethylene complex [π-C₅H₅Fe(CO)₂C₂H₄]⁺A^–. It is suggested that carbene intermediates are involved in these reactions. The chemical shifts of the methylene hydrogens in some complexes π-C₅H₅Fe(CO)₂CH₂R are discussed.