Molybdenum complexes containing substituted cyclopenta[l]phenanthrenyl ligand

The synthesis of new cyclopenta[l]phenanthrenyl complexes [(η5-C17H10Me)(η3-C3H5)Mo(CO)2] and [(η5-C17H9(COOMe)N(CH2)4)(η3-C3H5)Mo(CO)2] is described. Although these compounds are structural analogues their reactivity is different. Protonation of [(η5-C17H10Me)(η3-C3H5)Mo(CO)2] gives a stable ionic compound [(η5-C17H10Me)Mo(CO)2(NCMe)2][BF4] while its analogue containing both tertiary amino and carboxylic ester groups [(η5-C17H9(COOMe)N(CH2)4)(η3-C3H5)Mo(CO)2] decomposes under the same conditions. [(η5-C17H10Me)Mo(CO)2(NCMe)2][BF4] reacts with cyclopentadiene to give a stable η4-complex [(η4-C5H6)(η5-C17H10Me)Mo(CO)2][BF4] that was successfully oxidized to the Mo(IV) dicationic compound [(η5-C5H5)(η5-C17H10Me)Mo(CO)2][Br][BF4].