In the pharmaceutical industry, the analysis of atropisomers is of considerable interest from a scientific and regulatory perspective. The compound of interest contains two stereogenic axes due to the hindered rotation around the single bonds connecting the aryl groups, which results in four potential configurational isomers (atropisomers). The separation of the four atropisomers is achieved on...

C(59)N magnetic fullerenes were formed inside single-wall carbon nanotubes by vacuum annealing functionalized C(59)N molecules encapsulated inside the tubes. A hindered, anisotropic rotation of C(59)N was deduced from the temperature dependence of the electron spin resonance spectra near room temperature. Shortening of the spin-lattice relaxation time T(1) of C(59)N indicates a reversible charg...

D. Direct Nuclear Spin-Spin Interactions in Free Molecules. Internuclear Spacings and Shapes of Molecular Vibrational Potential IS. Direct Nuclear Spin-Spin Interactions in Rigid Solids. Atomic Spacings and Bond Angles F. Nuclear Paramagnetic Resonance Line Widths in Liquids and Gases Collision Narrowing G. The Effect of Nuclear Motion on Nuclear Resonance Spectra in Crystals. Hindered Rotatio...

The infrared absorption spectra of methanol, ethanol, and n-propanol have been measured with prism instruments. Studies have been made of the vapors and of several dilute solutions. The methanol spectra, between 2 to 15 microns, prpvided a direct comparison with the other two alcohols and confirmed earlier work on the existence of a number of lowintensity bands. The two other alcohols were stud...

The PhoQP two-component system is a signaling complex essential for bacterial virulence and cationic antimicrobial peptide resistance. PhoQ is the histidine kinase chemoreceptor of this tandem machine and assembles in a homodimer conformation spanning the bacterial inner membrane. Currently, a full understanding of the PhoQ signal transduction is hindered by the lack of a complete atomistic str...

The hindered internal rotations around the partial carbon-carbon double bond, nitrogen-carbon and carbon-carbon single bonds within the 2-(2-chloro-phenothiazine-l-yl)-3-(triphenylphosphoranylidene) butandioate has been experimentally studied by the dynamic H NMR spectroscopic in variable temperatures. The activation (∆H, ∆S, ∆G) and kinetic (kc, Ea) parameters have been calculated in a series ...

The rearrangement of N-p-toluenesulfonyl 2-tert-butyldiphenylsilylmethyl-substituted azetidines into 3-tert-butyldiphenylsilyl-substituted pyrrolidines under Lewis acid conditions in dichloromethane involves 1,2-migration of silicon through a siliranium ion. The formation of siliranium ion was discovered not to be in concert with σ(C-N) cleavage from stereochemical analysis of the pyrrolidine p...

The rotational dynamics of HCl in liquid Ar has been studied by means of molecular-dynamics simulations. We calculate the lifetimes of weakly bound HCl-Ar dimers induced by the anisotropic pair interaction. It is shown that, although lifetimes are small with respect to the reorientational decorrelation, the time interval between the breaking down and formation of the next dimer is negligibly sm...