Comparative reactivity study of cyclopentadienyl and fulvalene molybdenum complexes

The reactions of cis-1,1′-[η5:η5-(C5H3CO2Me)2]Mo2(CO)6 (1), in the presence of 1 equiv. of Me3NO, and [(η5-C5H4CO2Me)Mo(CO)3]2 (2) with dppe produce CO labilization and formation of the dinuclear zwitterions trans-1,1′-[η5:η5-(C5H3CO2Me)2]Mo2(CO)5(dppe) (3) and disproportionation species [(η5-C5H4CO2Me)Mo(CO)2(dppe)]+ [(η5-C5H4CO2Me)Mo(CO)3]− (4), respectively. Using the same method, the reactions of trans-1,1′-[η5:η5-(C5H3CO2Me)2]Mo2(CO)6I2 and (η5-C5H4CO2Me)Mo(CO)3I with PPh3 in the presence of 1 and 2 equiv. of Me3NO yield trans-1,1′-[η5:η5-(C5H3CO2Me)2]Mo2(CO)4(PPh3)2I2 (5) and (η5-C5H4CO2Me)Mo(CO)2(PPh3)I (6). The reactions of the several anionic carbonyl species {trans-1,1′-[η5:η5-(C5H3CO2Me)2]Mo2(CO)6}2−, [(η5:η5-C10H8)W2(CO)6]2− and [(η5-C5H4CO2Me)Mo(CO)3]− with S2Ph2 give rise to the thiolate–fulvalene complexes cis-1,1′-[η5:η5-(C5H3CO2Me)2]Mo2(CO)4(μ-SPh)2 (7) and (η5:η5-C10H8)W2(CO)6(SPh)2 (8) and the thiolate-bridged dimer [(η5-C5H4CO2Me)Mo(CO)(μ-SPh)]2 (9). Treatment of 6 with 1 equiv. of HCCCCH and with (η5-C5H5)Mo(CO)(dppe)(CCCCH), in the presence of CuI at room temperature, afford the cyclopentadiene complexes (η5-C5H4CO2Me)Mo(CO)2(PPh3)(CCCCH) (10) and (η5-C5H4CO2Me)(PPh3)(CO)2Mo(CCCC)Mo(CO)(dppe)(η5-C5H5) (11), respectively. The reaction of (η5-C5H5)Mo(CO)(dppe)(CCCCH) with Co2(CO)8 yields [Co2{μ-HC2CC[Mo(CO)(dppe)(η5-C5H5)]}(CO)6] (12). All the new compounds have been characterized by analytical and spectroscopic methods.