SYNTHESIS AND CHARACTERIZATION OF DOUBLE MCOC2 AND MFECOS (M=MO, W) TETRAHEDRAL CLUSTER COMPLEXES BRIDGED BY VARIOUS BISCYCLOPENTADIENYL LIGANDS

The bridged double tetrahedral clusters [RPhC2MCo(CO)(5)(eta(5)-C5H4)] (2)[C(O)CH2CH2C(O)] (1a M = Mo, R = Ph; 1b Mo, p-MeC6H4; 1c Mo, m-MeOC 6H4; 1d W, Ph), Ph2C2MCo(CO)(5)(eta(5)-C5H4)](2)[p-C(O)C6H4C(O)-p] (2a M = Mo; 2b W) and [Ph2C2MCo(CO)(5)(eta(5)-C5H4)](2)[o-CH2C6H4CH2-o] ( 4) were synthesized from single tetrahedral clusters RPhC2Co2(CO)(6) a nd corresponding bridging intermediate reagents [NaM(CO)(3)(eta(5)-C5H 4)](2)Z (Z = C(O)CH2CH2C(O)), p-C(O)C6H4C(O)-p, o-CH2C6H4CH2-o), where as those clusters [FeMCoS(CO)(8)(eta(5)-C5H4)](2)[p-C(O)C6H4C(O)-p] (3 a M = Mo, 3b W), [FeMCoS(CO)(8)(eta(5)-C5H4)(2)[o-CH2C6H4CH2-o] (5) an d [FeMoCoS(CO)(8)(eta(5)-C5H4)](2)[Me2SiOSiMe2] (6) were prepared by r eactions of a single tetrahedral cluster FeCo2(CO)(9)(mu(3)-S) with br idging intermediate reagents [NaM(CO)(3)(eta(5)-C5H4)](2)Z (Z = p-C(O) C6H4C(O)-p, o-CH2C6H4CH2-o) or [LiMo(CO)(3)(eta(5)-C5H4)](2) [Me2SiOSi Me2], respectively. Further reactions of 3a-b with reducing agent NaBH 4 gave corresponding bridged double clusters MCoS(CO)(8)(eta(5)-C5H4)] (2)[p-CH(OH)C6H4CH(OH)-p] (8a M = Mo; 8b W), whereas 1a reacted with N aBH4 afforded 2Mo-Co(CO)(5)(eta(5)-C5H4)](2)[CH(OH)CH2CH2CH(OH)] (7), which could be converted to its ether cluster derivative Co(CO)(5)(eta (5)-C5H4)(2)][alpha-CHCH2CH2CH-alpha] (9). All the new clusters 1-9 ha ve been characterized by elemental analysis, IR and H-1 NMR spectrosco py, whereas new terephthaloylbis(cyclopentadienylsodium) used to prepa re intermediate reagents [NaM(CO)(3) (eta(5)-C5H4)](2)[p-C(O)C6H4C(O)- p] has been isolated and characterized by IR and H-1 NMR spectroscopy. (C) 1997 Elsevier Science Ltd.