Metathesis of Alkyl Radicals and Alkenes–a Novel Elementary Reaction of Alkyl Radicals

✍ Scribed by Priv.-Doz. Dr. Jürgen O. Metzger

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 236 KB
• Volume: 25
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/anie.198600801

✦ Synopsis

pretation is supported by the significantly lengthened Si-C bonds (I99 pm compared with 187 pm for the single bond) and the expanded angle at the tertiary C atoms (C-C-C between 104.2 and 106.5", Si-C-C between 110.9 and 114.8"). The Si-Si distance in 1 corresponds to a Pauling bond order of 0.45 and, as in the case of hexa-terr-butylcyclotrisilane,"' the sum of the bond orders for the Si atom in 1 (2.55) is considerably less than the expected value of four.

The variability in the distance between Si atoms is remarkable. The distance for a bonding interaction found in I is larger than that in fibrous SiOz (258 pm@'), although the interaction in the latter case is repulsive. The extreme case of the approach of Si atoms toward one another as a consequence of their surrounding was recently found in cyclosiloxanes (-R2Si-0-),."] In that case, the Si-Si distance is shorter (231 pm) than that of a Si-Si single bond.