Compounds (eta-C5R5)Fe[eta-9-(Me2S)-7,8-C2B9H10] (R = H, Me) and (eta-C4Me4
)Co[eta-9-(Me2S)-7,8-C2B9H10] were synthesized by the reactions of Na[9-(Me
2S)-7,8-C2B9H10] with complexes [(eta-C5H5)Fe(MeCN)(3)]PF6, [(eta-C5Me5)Fe(
MeCN)(3)]BF4, and [(eta-C4Me4)Co(MeCN)(3)]PF6, respectively.