Hetero- and homobimetallic M/Ni, M/M (M = Mo, W) mu-alkyne complexes containing functionally substituted cyclopentadienyl ligands. Crystal structure of eta(5)-2,4-(NO2)(2)C6H3NHNC(Me)C5H4(CO)(2)WFe2H(mu(3)-S)(CO)(6)

While reaction of [eta (5)-RC5H4(CO)(3)Mo](2), PhC equivalent to CPh and Cp 2Ni yields Mo/Ni hetero- and Mo/Mo homobimetallic complexes [eta (5)-RC5H4( CO)(2)MoNiCp](mu -C2Ph2) [(1a) R = MeCO; (1b) R = MeO2C] and [eta (5)-RC5H4 (CO)(2)Mo](2)(mu -C2Ph2) [(2a) R = MeCO; (2b) R = MeO2C], reaction of [eta (5)-RC5H4(CO)(3)W](2), PhC=CPh and Cp2Ni give W/Ni heterobimetallic compoun ds [eta (5)-RC5H4(CO)(2)WNiCp](mu -C2Ph2) [(3a) R = MeCO; (3b) R = EtO2C] w ithout an appreciable amount of W/W homobimetallic complexes [eta (5)-RC5H4 (CO)(2)W](2)(mu -C2Ph2) [(4a) R = MeCO; (4b) R = EtO2C]. However, (4a) and (4b) can be simply obtained from [eta (5)-RC5H4(CO)(3)W](2) and PhC=CPh in quite good yields. Further, reactions of (1a) and (3a) with 2,4-(NO2)(2)C6H 3NHNH2 produce phenylhydrazone derivatives [eta (5)-2,4-(NO2)(2)C6H3NHNC(Me )C5H4(CO)(2)MNiCp](mu -C2Ph2) [(5a) M = Mo, (5b) M = W], whereas reactions of (2a) and (4a) with 2,4-(NO2)(2)C6H3NHNH2 give corresponding derivatives [eta (5)-2,4-(NO2)(2)C6H3NHNC(Me)C5H4(CO)(2)MM(CO)(2)C5H4COMe-eta (5)](mu - C2Ph2) [(6a) M = Mo, (6b) M = W] and [eta (5)-2, 4-(NO2)(2)C6H3NHNC(Me)C5H4 (CO)(2)M](2)(mu -C-2 Ph-2) [(7a) M = Mo, (7b) M = W]. The crystal structure of eta (5)-2,4-(NO2)(2)C6H3NHNC(Me)C5H4(CO)(2)WFe2H (mu (3)-S)(CO)(6) (8) has been determined by X-ray diffraction.