Synthesis and characterization of substituted cyclopentadienide ligands that may form chelates or metal dimers

Nine different substituted cyclopentadienyl ligands, which have substituents that may either chelate or bridge to second metal center, have been prepared from nucleophilic substitution reactions of esters or alkyl halides with NaCp. The sodium or thallium salts of these ligands were isolated as solids and characterized by H-1 NMR. The alkyl halide and NaCp reaction proved to yield the purer salts of the ligands because of the milder reaction conditions. These salts were reacted futher with Mn(CO)(5)Br to form the corresponding manganese tricarbonyl derivatives (i.e. (C(5)H(4)R)Mn(CO)(3); where R=C(O)CH2OCH3, C(O)CH2SCH3, C(O)CH2CH2SCH3, CH2CO2CH3, CH2CO2CH2CH3, CH2CH2CO2CH3, CH2CH2CO2CH2CH3, CH2CH2O2CCH3, and CH2CH2OCH3) and Na(C5H4C(O)CH2OCH3) was reacted with Co-2(CO)(8) to form (C5H4C(O)CH2OCH3)Co(CO)(2). The manganese and cobalt compounds were characterized by elemental analysis, IR, H-1, and C-13 NMR spectra.