Preparation and reactivity of (η-arene)tricarbonylmanganese cations bearing functional substituents

Abstract

Tricarbonyl(η-methoxy- and tricarbonyl(η-halogeno-benzene)manganese salts have been obtained from the appropriate arenes with bromopentacarbonylmanganese and aluminium chloride. The ease of nucleophilic substitution increases sharply in the series of halogenoarene compounds linked to (OC)₃Cr < (cp)Fe⁺ < (OC)₃Mn⁺(cp =η-cyclopentadienyl). The high reactivity of the manganese complexes is utilised in the preparation of other functionally substituted arene complexes by reaction with amines or anionic nucleophiles. l.r. and n.m.r. study of the amino-substituted arene complexes establishes partial nitrogen to ring double bonding.