| Abstract: | Bis(cyclopentadienyl)methane-bridged Dinuclear Complexes. VIII. Dinuclear Cobalt Complexes with the Dianion of Bis(cyclopentadienyl)methane and Bis(tetramethylcyclopentadienyl)dimethylsilane as Bridging Ligands The dinuclear cobalt complex CH2(C5H4)2]Co(CO)2]2 ( 4 ) which is obtained from Co(CO)4I] ( 2 ) and Li2CH2(C5H4)2] ( 3 ) in 75% yield reacts with PMe3, PiPr3, P2Me4, Me2PCH2CH2PMe2 and (EtO)2POP(OEt)2, to the compounds 5–9 substituting one CO ligand per cobalt atom. Oxidative addition of CH3I to CH2(C5H4)2]Co(CO)(PMe3)]2 ( 5 ) leads to the formation of the dinuclear cobalt(III) complex CH2(C5H4)2]Co(COCH3)(PMe3)I]2 ( 11 ). The reaction of 4 with iodide generates CH2(C5H4)2]Co(CO)I2]2 ( 12 ) which with PMe3, P(OMe)3, P(OiPr)3, and CNMe reacts under CO substitution to CH2(C5H4)2]Co(L)I2]2 ( 13–16 ) and with PMe2H to {CH2(C5H4)2]Co(PMe2H)3]2}I4 ( 17 ). The electrophilic addition reactions of NH4PF6 and CH3I to CH2(C5H4)2]Co(PMe3)2]2 ( 20 ) produce the complex salts {CH2(C5H4)2]CoR(PMe3)2]2}X2 ( 21 : R = H; 22 : R = CH3). From 22a (X = I) and LiCH3 the dinuclear tetramethyldicobalt compound CH2(C5H4)2] · Co(CH3)2(PMe3)]2 ( 23 ) is obtained which further reacts, via the intermediate 24 , to the chiral complex {CH2(C5H4)2] · CoCH3(PMe3)P(OMe)3]2}(PF6)2 ( 25 ). The reaction of 20 with C2(CN)4 and E- or Z-C2H2(CO2Me)2 gives the olefin(trimethylphosphine) cobalt(I) derivatives 26 und 27 . The synthesis of the dinuclear compounds 31–38 with Me2Si(C5Me4)2]2? as the bridging unit is also described. |
