Nucleophilic Carbene Complexes of Manganocene

The reaction of the sterically demanding nucleophilic carbenes 1,3-bis(2,6-dimethyl-4-bromophenyl)imidazol-2-ylidene ( 1 ) and 1,3-dimesitylimidazol-2-ylidene ( 3 ) with manganocene resulted in complexes of the type (η 2 -C 5 H 5 )(η 4 -C 5 H 5 )Mn(carbene) ( 2 and 4 ). The reaction of equimolar amounts of the less sterically demanding nucleophilic carbene tetramethylimidazol-2-ylidene ( 5 ) afforded the bis(carbene)complex (η 1 -C 5 H 5 )(η 2 -C 5 H 5 )Mn(carbene) 2 ( 6 ). The structures of these complexes were determined by single-crystal X-ray diffraction.