SILYL DERIVATIVES OF THE MIXED SANDWICHES CYCLOPENTADIENYL MANGANESE BENZENE AND CYCLOPENTADIENYL MANGANESE BIPHENYL, CPMN(C6H6) AND CPMN(C6H5-PH)

Mixed manganese sandwich complexes containing a silyl-substituted cycl opentadienyl ring, e. g. (eta(5)-C5H4-R)Mn(eta(6)-C6H6) (3a - c) and ( eta(5)-C5H4-R)Mn(eta(6)C(6)H(5)-Ph) (4a - c); (R = SiMe3 (a), Si2Me5(b ) and SiMe2'Bu (c)), were obtained in low yield via intermediates {(et a(5)-C5H4-R)MnCl} and their reaction with phenyl Grignard reagents. Us e of the 4-trimethylsilyl-phenyl magnesium halide in the reaction with the intermediate {CpMnCl} led to complexes with silyl-substituted are ne rings, CpMn(eta(6)-C6H5-R') (5a) and CpMn(eta(6)R'-C6H5-C6H5-R') (6 a); (R' = SiMe3 (a)). Dilithiation of CpMn(C6H6) (1) and subsequent re action with a chlorosilane gave (eta(5)-C5H4-R)Mn(eta(6)-C6H5-R') (7a, b); (R = R' = SiMe3 (a), Si2Me5 (b)). A cyclophane 8 in which five- an d six-membered ring are linked through a -Me2Si-SiMe2-bridge was obtai ned using 1,2-dichloro-tetramethyldisilane. The mixed manganese sandwi ch complexes were thoroughly characterized by H-1, C-13, Si-29 and Mn- 55 NMR spectroscopy. The Mn-55 spectra can be used to detect low-yield side-products.