Chemistry of the metal carbonyls. Part XXXVIII. Reactions of dicarbonyl-π-cyclopentadienylferrate(–II) with polyfluoroaromatic compounds

Abstract

Reactions between the anion [π-C₅H₅Fe(CO)₂]^– and compounds C₆F₅X (X = F, Cl, Br, or I) have given significant amounts of p-HC₆F₄·Fe(CO)₂(π-C₅H₅), in addition to the expected C₆F₅·Fe(CO)₂(π-C₅H₅). With C₆F₅X (X = CN or CO₂Et), para-substitution occurs to yield the compounds p-XC₆F₄·Fe(CO)₂(π-C₅H₅); with C₆F₅CN the complex H(CN)C₆F₃·Fe(CO)₂(π-C₅H₅) is also obtained in small amount. Pentafluorophenylhydrazine reacts with [π-C₅H₅Fe(CO)₂]^– to afford p-HC₆F₄·Fe(CO)₂(π-C₅H₅). With o-C₆F₄X₂(X = CN or CO₂Et), substitution occurs in the 4-position to give the complexes X₂C₆F₃·Fe(CO)₂(π-C₅H₅). With o-C₆F₄(CN)₂, the anions Mn(CO)₅^– and Re(CO)₅^– react similarly to give (NC)₂C₆F₃·M(CO)₅(M = Mn or Re). Treatment of o-C₆F₄I₂ with [π-C₅H₅Fe(CO)₂]^– affords a mixture of three products, tentatively identified as o-H₂C₆F₃·Fe(CO)₂(π-C₅H₅), o-IC₆F₄·Fe(CO)₂(π-C₅H₅), and o-HC₆F₄·Fe(CO)₂(π-C₅H₅).