ORGANOMETALLOIDAL DERIVATIVES OF THE TRANSITION-METALS .24. CHEMICAL AND STRUCTURAL INVESTIGATIONS ON (FERROCENYLACYL)SILANES

(Ferrocenylacyl)silanes, (η5-C5H5)Fe(η5-C5H4)COSiR3 (R3 = Me3, Me2Ph, MePh2, Ph3), have been synthesized and their chemical, physical, and structural properties investigated. The compounds exhibit no photochemistry and are not subject to base-catalyzed rearrangements. Attempts to synthesize acyldisilanes, FcCOSiRʹ2SiR3, via hydrolysis of the corresponding ferrocenyldisilyldithianes, resulted in the formation of only FcCOSiR3. In a similar manner attempts to synthesize FcCOSiMe2SiMe2SiMe3 and FcCOSi(SiMe3)3 yielded only FcCOSiMe3. Basicity measurements, via H-bonding to phenol, indicate the ferrocenyl group to be responsible for a major increase in the basicity of the acylsilanes. The structures of the four acyl complexes are reported and exhibit almost identical structural parameters about the carbonyl group, illustrating that the ferrocenyl group has a dominant steric effect upon the compounds. The steric bulk of the silyl groups is shown to be Ph3Si > Me3Si > Me2PhSi = MePh2Si. © 1990, American Chemical Society. All rights reserved.