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  2. Proton nuclear magnetic resonance - Wikipedia

    en.wikipedia.org/wiki/Proton_nuclear_magnetic...

    The CH 2 peak will be split into a doublet by the CH peak—with one peak at 1 ppm + 3.5 Hz and one at 1 ppm − 3.5 Hz (total splitting or coupling constant is 7 Hz). In consequence the CH peak at 2.5 ppm will be split twice by each proton from the CH 2. The first proton will split the peak into two equal intensities and will go from one peak ...

  3. Hückel's rule - Wikipedia

    en.wikipedia.org/wiki/Hückel's_rule

    Benzene, the most widely recognized aromatic compound with six delocalized π-electrons (4n + 2, for n = 1). In organic chemistry , Hückel's rule predicts that a planar ring molecule will have aromatic properties if it has 4 n + 2 π-electrons , where n is a non-negative integer .

  4. Nuclear magnetic resonance spectra database - Wikipedia

    en.wikipedia.org/wiki/Nuclear_magnetic_resonance...

    SDBS includes 14700 1 H NMR spectra and 13000 13 C NMR spectra as well as FT-IR, Raman, ESR, and MS data. The data are stored and displayed as an image of the processed data. Annotation is achieved by a list of the chemical shifts correlated to letters which are also used to label a molecular line drawing.

  5. Magnetic inequivalence - Wikipedia

    en.wikipedia.org/wiki/Magnetic_inequivalence

    For instance, magnetic inequivalence is found in 1,4-homodisubstituted butadienes. [2] It might be expected in a molecule such as a symmetrical 2,3,4,5-tetrasubstituted pyrrolidine , but less rigid and less flat sp 3 frameworks tend to show very weak long-range couplings (through 4 or more bonds) so as to not manifest much sign of magnetic ...

  6. 1,2,4,5-Tetrachloro-3-nitrobenzene - Wikipedia

    en.wikipedia.org/wiki/1,2,4,5-tetrachloro-3...

    1,2,4,5-Tetrachloro-3-nitrobenzene (tecnazene) is an organic compound with the formula HC 6 Cl 4 NO 2. It is a colorless solid. A related isomer is 1,2,3,4-tetrachloro-5-nitrobenzene. It is used as a standard for quantitative analysis by nuclear magnetic resonance. [4] [5]

  7. Triple-resonance nuclear magnetic resonance spectroscopy

    en.wikipedia.org/wiki/Triple-resonance_nuclear...

    Triple resonance experiments are a set of multi-dimensional nuclear magnetic resonance spectroscopy (NMR) experiments that link three types of atomic nuclei, most typically consisting of 1 H, 15 N and 13 C. These experiments are often used to assign specific resonance signals to specific atoms in an isotopically-enriched protein.

  8. How ‘Gladiator 2’ Sneakily Turns Denzel Washington Into an ...

    www.aol.com/gladiator-2-sneakily-turns-denzel...

    Israeli strike kills 5 journalists in Gaza, hospital says. News. Reuters. Dead body found in wheel well after United flight lands in Hawaii. Sports. Sports. Associated Press.

  9. Phosphorus-31 nuclear magnetic resonance - Wikipedia

    en.wikipedia.org/wiki/Phosphorus-31_nuclear...

    With a gyromagnetic ratio 40.5% of that for 1 H, 31 P-NMR signals are observed near 202 MHz on an 11.7-Tesla magnet (used for 500 MHz 1 H-NMR measurements). Chemical shifts are typically referenced to 85% phosphoric acid, which is assigned the chemical shift of 0, and appear at positive values (downfield of the standard). [2]