The detection of minor species in the presence of large amounts of similar main components remains a key challenge in analytical chemistry, for instance, to obtain isotopic fingerprints. As an alternative to the classical NMR scheme based on coherent excitation and detection, here we introduce an approach based on spin-noise detection. Chemical shifts and transverse relaxation rates are determi...

13C N M R spectra have been obtained f0r.a series of LnNi(CO)o-n derivatives (n = 0-3) where L = PR3, PPhzY, PPhY2, P(OR')3, and Pc13 (R = Me, Et, Bu, Ph; R' = Me, Et, l-Pr, Ph; Y = C1, Me, OMe, OPh). The effect upon the carbonyl chemical shift of the replacement of X by Y substituents in X3-nYnPNi(C0)3 derivatives appears to be additive, as is the effect of the sequential replacement of carbon...

Solid-state nuclear magnetic resonance (NMR) spectroscopy was applied to the membrane-bound form of a synthetic peptide representing the 23-residue N-terminal fusion peptide domain of the HIV-1 gp41 envelope glycoprotein. 1D solid-state NMR line width measurements of singly 13C carbonyl labeled peptides showed that a significant population of the membrane-bound peptide is well-structured in its...

Tetrahydrolipstatin (orlistat) (S)-1-[(2S,3S)-3-hexyl-4-oxooxetan-2-yl]methyl]dodecyl N-formyl-L-leucinate, a potent inhibitor of pancreatic lipase, is hydrophobic, amphipathic, and water-insoluble. It binds irreversibly to pancreatic lipases and inhibits fat absorption. The focus of this investigation is on the distribution of orlistat in emulsified fat and vesicular membranes such as might be...

2014 High resolution 13C NMR results for the organic conductor TTF[Ni(dmit)2]2 enriched by 13C isotope in Ni(dmit)2 molecules are reported. Variable temperature magic angle spinning experiments were performed between 160 and 295 K. Paramagnetic Knight shifts in the range 41-106.5 ppm at room temperature are observed for all Ni(dmit)2 carbon sites. These shifts are slightly temperature dependent...

The 13C NMR chemical shift of sp2 carbon atoms in acyclic alkenes was estimated with multilayer feedforward artificial neural networks (ANNs) and multilinear regression (MLR), using as structural descriptors a vector made of 12 components encoding the environment of the resonating carbon atom. The neural network quantitative model provides better results than the MLR model calibrated with the s...

Herein, an NMR spectral analysis was performed of a mixture diastereomeric acetals synthesized from 2-fluorobenzaldehyde and racemic 4-methylpentan-2-ol. The simulated 1H- 13C-NMR spectra individual diastereomers, as well their superimposed summed spectra, were compared with the obtained experimental spectra. Spin simulation proton signals particularly useful for assignment aromatic part molecu...