The first aim of the thesis was to synthesise and characterise several diiron cyclopentadienyl complexes with bridging aminocarbyne ligands featuring a common polar pendant on the carbynic nitrogen. Reactivity studies on these newly prepared complexes were carried out to observe if the polar moiety, upon decoordination of one of the CO ligands, could coordinate the iron centre in a hemilabile way creating an “on-demand” coordination vacancy on the metal. Then, several diiron cyclopentadienyl aminocarbyne complexes were prepared by substitution of one of the carbonyl moieties with labile ligands, that can be easily detached from the metal centre. Finally, all the complexes were tested as suitable catalysts for the reactions of hydration of nitriles and synthesis of β-hydroxynitriles.