Ferrocenecarboxylic acid
Ferrocenecarboxylic acid is the organoiron compound with the formula. It is the simplest carboxylic acid derivative of ferrocene. It can be prepared in two steps from ferrocene by acylation with a 2-chlorobenzoyl chloride followed by hydrolysis.
On a two-dimensional surface, most carboxylic acids form hydrogen-bonded dimers. Ferrocenecarboxylic acid instead forms a mixture of dimers and cyclic pentamers and organizes into a quasicrystalline order with fivefold symmetry, the first known molecular quasicrystal.
Reactions and derivatives
The pKa of ferrocenecarboxylic acid is. The acidity increases more than a thousand-fold, to upon oxidation to the ferrocenium cation.By treatment with thionyl chloride, the carboxylic acid anhydride is produced.
Derivatives of ferrocenecarboxylic acid are components of some redox switches.