(η5-Carb­oxy­cyclo­penta­dien­yl)(η7-cyclo­hepta­trien­yl)manganese(I) hexa­fluorido­phosphate

The title compound, [Mn(C7H7)(C6H5O2)]PF6 or [(Cht)Mn(Cp’CO2H)]PF6, with Cht = cyclo­hepta­trienyl and Cp’ = C5H4, is an air-stable, purple, heteroleptic, cationic sandwich complex with manganese in oxidation state +I and π-coordinating cyclo­hepta­trienyl and cyclo­penta­dienyl ligands. The latter ligand carries the carb­oxy­lic acid functionality. This ‘tromancenium-8-carb­oxy­lic acid’ with hexa­fluorido­phosphate as counter-ion represents a rare case of a cationic carb­oxy­lic acid. Structurally, this organometallic carb­oxy­lic acid displays the common motif of planar Osp2⋯H—Osp3/Osp3—H⋯Osp2 hydrogen-bonded carb­oxy­lic acid dimers with anti-oriented metallocenyl moieties, the cationic charge of which is balanced by octa­hedrally shaped hexa­fluorido­phosphate anions. Positional disorder is observed in the cyclo­hepta­trienyl ring and the PF6− anion.Unlabelled Image