All psyched up: A flexible and general pure shift experiment (PSYCHE) has been developed that offers superior sensitivity, spectral purity, and tolerance of strong coupling over existing methods for broadband homonuclear decoupling. The partial spectra of estradiol in [D6]DMSO obtained by normal 1H NMR spectroscopy and PSYCHE are shown for comparison
The connection of lipophilic gallic acid derivatives at the 5,5'- or 6,6'-positions of the rigid 2,6-bis(1-ethyl-benzimidazol-2-yl)pyridine core provides two pro-mesogenic tridentate ligands L10 and L12, whose molecular shapes, anisometries, and directional intermolecular pi-stacking can be tuned. X-ray diffraction data in the crystalline state, combined with solution 1H NMR measurements, show that complexation with trivalent lanthanides, Ln(III), produces the neutral hemi-disklike complexes [Ln(Li)(NO3)3] (i = 10, 12), which dimerize to give the rodlike bimetallic complexes [Ln2(Li)2(NO3)6] at lower temperature. The relevant thermodynamic parameters for the latter process depend on the nature of the ligand, the size of the metal ion, and the strength of the intermolecular interactions involved in the condensed phase. These three-dimensional models obtained for the complexes in the crystals and in solution are eventually confronted with small-angle XRD profiles recorded in the intermediate thermotropic liquid crystalline phase, in which the rigidity of the packed polyaromatic cores is maintained, while the alkyl chains are molten. According to the specific geometries and nuclearities of the molecular complexes, three types of mesophases (lamellar, columnar, and cubic) can be induced, which provides a direct correlation between the microscopic arrangements and the macroscopic ordering in lanthanide-containing metallomesogens.
Covering: up to 2018With contributions from the global natural product (NP) research community, and continuing the Raw Data Initiative, this review collects a comprehensive demonstration of the immense scientific value of disseminating raw nuclear magnetic resonance (NMR) data, independently of, and in parallel with, classical publishing outlets. A comprehensive compilation of historic to present-day cases as well as contemporary and future applications show that addressing the urgent need for a repository of publicly accessible raw NMR data has the potential to transform natural products (NPs) and associated fields of chemical and biomedical research. The call for advancing open sharing mechanisms for raw data is intended to enhance the transparency of experimental protocols, augment the reproducibility of reported outcomes, including biological studies, become a regular component of responsible research, and thereby enrich the integrity of NP research and related fields.
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