Organometallic complexes in synthesis. Part III. The reaction of concentrated sulphuric acid with tricarbonylcyclohexa-1,3-dieneiron complexes: a preparation of certain alkyltricarbonyl-π-cyclohexadienyliron salts

Abstract

Concentrated sulphuric acid converts tricarbonyliron complexes of 1- or 2-methoxycyclohexa-1,3-dienes, and some methylated derivatives, into tricarbonyl-π-cyclohexadienyliron salts. The products are independent of the positions of the unsaturation in the neutral complexes. Several methylcyclohexa-1,3-diene complexes, when reacted similarly, are converted into isomers. The method is applicable to the production, in some cases, of pure complexes and salts not obtainable by other methods.