At the Experimental Limit of the NMR Conformational Analysis: 29Si and 13C NMR Study of the Conformational Equilibrium of 1-Phenyl-1-tert-butylsilacyclohexane.

Erich KleinpeterMatthias HeydenreichBagrat A Shainyan

Published in: Organic letters (2020)

The low temperature (95 K) NMR study of 1-Ph-1-t-Bu-silacyclohexane (1) showed the conformational equilibrium to be extremely one-sided toward thePhax,t-Bueq conformer. The barrier to interconversion has been measured (4.2-4.6 kcal/mol) and the conformational equilibrium [Δν = 1990.64 ppm (29Si), 618.9 ppm (13C), 1-Phax:1-Pheq = (95.6-96.6%):(3.4-4.4%), K = 25 ± 3, ΔG° = -RT ln K = 0.58-0.63 kcal/mol] analyzed. The assignment and quantification of the NMR signals is supported by MP2 and DFT calculations.

Keyphrases

molecular dynamics
molecular dynamics simulations
density functional theory
magnetic resonance
high resolution
solid state
single molecule
molecular docking
mass spectrometry