The reactions of (η-C5H5)Co(CO)2
with the diynes hexa-2,4-diyne and 1,4- diphenylbutadiyne
give three isomers of the cyclopentadienone complexes (C5H5)Co[(RC2C2R)2CO],
R = Me or Ph, and two isomers of the tris-alkyne complexes (C5H5)2Co2(RC2C2R)3CO,
R = Me or Ph. Organic products of formula (RC2C2R)3,
R = Me or Ph, (MeC2C2Me)5, and (PhC2C2Ph)3CO
have been isolated also. Two isomers of (RC2C2R), were
separated and were identified as the 1,2,4-(R)3-3,5,6-(C2R)3-
and the 1,3,5-(R)3-2,4,6-(C2R)3-benzenes. The
compound (PhC2C2Ph)3CO is believed to be tris(phenylethynly)triphenylcycloheptatrienone,
and (MeC2C2Me)5 is probably a polycyclic aromatic
compound. Thermal degradation of the complexes (C5H5)2CO2(RC2C2R)3CO
gives the substituted benzenes (RC2C2R)3. ��� The reaction of (η-C5H5)Rh(CO)2 and hexa-2,4-diyne gives the
cyclopentadienone complex(C5H5)Rh[(MeC2C2Me)2CO]
and the cycloheptatrienone complex (C5H5)Rh[(MeC2C2Me)3CO].Two
isomers of the substituted benzene (MeC2C2Me)3
were obtained also.