The Extended Czjzek Model (ECM) is applied to the distribution of NMR parameters of a simple glass model (sodium metaphosphate, NaPO3) obtained by Molecular Dynamics (MD) simulations. Accurate NMR tensors, Electric Field Gradient (EFG) and Chemical Shift Anisotropy (CSA), are calculated from Density Functional Theory (DFT) within the well-established PAW/GIPAW framework. Theoretical results are...

The H and C Nuclear Magnetic Resonance (NMR) spectra of the retinyl chromophore in rhodopsin are investigated by using Quantum Mechanics/Molecular Mechanics (QM/MM) hybrid methods at the Density Functional Theory (DFT) B3LYP/631G*:Amber level, in conjunction with the Gauge Independent Atomic Orbital (GIAO) method for the ab initio Self-Consistent-Field (SCF) calculation of NMR chemical shifts. ...

Minor products in the reaction between substituted 1,3-diiminoisoindolines and 2,5-diamino-3,4-dicyanothiophene were identified as the nickel seco-tribenzoporphyrazines 4 and 5, which have been characterized by UV-vis, MCD, NMR, and mass spectroscopy. Experimentally observed tetraazachlorin-type UV-vis spectra of new seco-tribenzoporphyrazines were explained on the basis of DFT and TDDFT calcul...

Molecular geometry, electronic spectra, infrared and NMR spectra of [Ru(OAc)(2mqn)2NO] (H2mqn = 2methyl-8-quinolinol) isomers were studied with density functional theory (DFT) at B3LYP level with 6311++G(d,p) and Aug-cc-pVDZ-PP as basis set. a r t i c l e i n f o

Background: Aescin, a natural mixture of saponins occurring in Aesculus hippocastanum, exhibits important flebotonic properties, being used in the treatment of chronic venous insufficiency in legs. The inclusion of aescin into cyclodextrins (CDs) is a technical solution for its incorporation into the textile of stockings, but details of the physicochemistry of these host-guest systems are lacki...

3-Ishwarone, (1), a sesquiterpene with a rare ishwarane skeleton, was isolated from Peperomia scandens Ruiz & Pavon (Piperaceae). Its structure was unambiguously determined by 1D- and 2D-NMR and infrared analyses, as well as by comparative theoretical studies which involved calculations of 13C-NMR chemical shifts, using the Density Functional Theory (DFT) with the mPW1PW91 hybrid functional and...

Here we describe the rapid identification and prioritization of novel active marine natural products using an improved dereplication strategy. During the course of our screening of marine natural product libraries, a new cyclic trihydroxamate compound, thalassosamide, was discovered from the α-proteobacterium Thalassospira profundimaris. Its structure was determined by 2D NMR and MS/MS experime...

We demonstrate that solid-state NMR spectra of challenging nuclei with a low gyromagnetic ratio such as yttrium-89 can be acquired quickly with indirect dynamic nuclear polarization (DNP) methods. Proton to (89)Y cross polarization (CP) magic angle spinning (MAS) spectra of Y(3+) in a frozen aqueous solution were acquired in minutes using the AMUPol biradical as a polarizing agent. Subsequently...

This paper reports the (1)H, (13)C and (15)N NMR experimental study of five benzimidazoles in solution and in the solid state ((13)C and (15)N CPMAS NMR) as well as the theoretically calculated (GIAO/DFT) chemical shifts. We have assigned unambiguously the "tautomeric positions" (C3a/C7a, C4/C7 and C5/C6) of NH-benzimidazoles that, in some solvents and in the solid state, appear different (bloc...