Essential Practical NMR for Organic Chemistry

PeakAL: Protons I Have Known and Loved - Fifty Shades of Grey-Market Spectra

“…[86] When we began this investigation our knowledge of NMR was limited, as was our experience interpreting spectra. The sophisticated and highly regarded Mestrelab software may, in retrospect, have inspired unrealistic expectations that interpreting spectra would be simple, even intuitive.…”

Rare Ellagic Acid Sulphate Derivatives from the Rhizome of Geum rivale L.—Structure, Cytotoxicity, and Validated HPLC-PDA Assay

“…A preparative sample (300 g) of the dried and grinded plant material was exhaustively extracted with acetone-water 70:30 (v/v) at room temperature (22)(23)(24)(25) • C) by mechanical shaking (6 × 3 L × 8 h). The combined acetone-water extracts were concentrated in vacuum until complete removal of acetone and then extracted with ethyl acetate (6 × 100 mL) to remove less polar constituents.…”

“…As for the C-4 carbon signal the large upfield shift (δC = −3.1) was found in comparison with that of the corresponding signal of free ellagic acid [12], the proposed substitution position of the sulphate group was further confirmed. The remaining assignments for aromatic carbons C(2), C(2′), C(6), and C(6′), as well as for carbonyl carbons C(7) and C(7′), were deduced by applying the known substituent parameters and basic additive rules [22] for predicting the chemical shifts of atomic nuclei in organic compounds. Eventually, compound 1 was identified as 3,3′-trimethoxy-4-sulphoxyellagic acid potassium salt (Figure 1).…”

Identification of equilibrium state of hydroxyl protons in vodkas by 1H NMR spectroscopy

“…NMR spectroscopy principle of operation is based on the usage of magnetic properties of some atomic nuclei, being able to resonate at characteristic frequencies of electromagnetic spectrum in external magnetic field and, that allows to identify nuclei in different chemical environment ( [1,11,13,14] in solutions.…”