Silyl Derivatives of the Mixed Sandwiches Cyclopentadienyl Manganese Benzene and Cyclopentadienyl Manganese Biphenyl, CpMn(C6H6) and CpMn(C6H5-Ph)

Mixed manganese sandw ich complexes containing a silyl-substituted cyclopentadienyl ring, e. g. (rj5 -C5 H4-R)Mn(7/6-C6H6) (3a c) and (775-C 5H4-R)M n(r/6-C6H5-Ph) (4a c); (R = SiM e3 (a), Si2M e_5 (b) and SiM e^'Bu (c)), were obtained in low yield via interm ediates {(r^-CsH*R)M nCl} and their reaction with phenyl G rignard reagents. Use o f the 4-trim ethylsilyl-phenyl m agnesium halide in the reaction with the interm ediate {CpM nCl} led to complexes with silylsubstituted arene rings, CpMn(?76-C6H5-R ’) (5a) and C p M n ^ -R -C ö H s-C ftH s-R ) (6a); (R' = SiM e3 (a)). Dilithiation o f C p M n ^ H ^ ) (1) and subsequent reaction w ith a chlorosilane gave (?75-C5H4-R)Mn(776-C6H5-R') (7a,b); (R = R' = SiM e3 (a), S iiM es (b)). A cyclophane 8 in which fiveand six-membered ring are linked through a -M e2Si-SiM e?bridge was obtained using 1,2-dichloro-tetram ethyldisilane. The mixed manganese sandw ich com plexes were thoroughly characterized by 'H , i3C, 29Si and 55M n N M R spectroscopy. The ^ M n spectra can be used to detect low-yield side-products.