Abstract
A dynamic process has been detected in the solution 13C-NMR spectra oftBu-Si(iPr)3 (4) in the temperature range -145 °C to -163 °C, the corresponding free energy of activation being 5.5 kcal mol−1. Molecular mechanics calculations have identified three types of conformations that are markedly more stable than all the others, but the one with the highest symmetry cannot be populated, as is evident from the appearance of the spectrum at low temperature. This spectrum can be interpreted in terms of restricted rotation of the tert-butyl group and of the isopropyl groups, leading to a structure centered around the (a,g,-g) conformation. In the case of the analogous (iPr)3SiCl derivative (5), this dynamic process was not observed in solution, but an appropriate spectrum for the same (a,g,-g) conformation was obtained by the solid-state CP-MAS NMR spectroscopy at -100 °C.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
