Mass spectra of cobalt carbonyl complexes

The mass spectra of the following acetylenic derivatives of Co2(CO)8 are reported: Co2(CO)6C2H2Co2(CO)6C 2,(CH3)2, Co2(CO)6 C2(CH2Cl)2, Co2(CO)6C2 (CF3)2, Co2(CO)2C2(C6H5)2 and Co2(CO)6C2(COOCH3)2. The effect of different C2RR′ on fragmentation modes is investigated. When R and R′ are aromatic groups, the major controlling factor is the stability of charged fragments; in other cases, it seems to be the loss of a stable neutral moiety. Transfer processes of alkoxylic groups are observed in Co2(CO)6C2(COOCH3)2, as well as in Co3(CO),9CCOOCH3, and Co3(CO)9CCOOC2H5. It is suggested that both cobalt and carbon atoms may be the migration sites.