enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Proton nuclear magnetic resonance - Wikipedia

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

    The spectrum would have two signals, each being a doublet. Each doublet will have the same area because both doublets are produced by one proton each. The two doublets at 1 ppm and 2.5 ppm from the fictional molecule CH−CH are now changed into CH 2 −CH: The total area of the 1 ppm CH 2 peak will be twice that of the 2.5 ppm CH peak.

  3. Doublet state - Wikipedia

    en.wikipedia.org/wiki/Doublet_state

    In quantum mechanics, a doublet is a composite quantum state of a system with an effective spin of 1/2, such that there are two allowed values of the spin component, −1/2 and +1/2. Quantum systems with two possible states are sometimes called two-level systems .

  4. Nuclear magnetic resonance spectroscopy - Wikipedia

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

    The NMR sample is prepared in a thin-walled glass tube – an NMR tube. An NMR spectrometer typically consists of a spinning sample-holder inside a very strong magnet, a radio-frequency emitter, and a receiver with a probe (an antenna assembly) that goes inside the magnet to surround the sample, optionally gradient coils for diffusion ...

  5. File:NMR J-coupling trees.svg - Wikipedia

    en.wikipedia.org/wiki/File:NMR_J-coupling_trees.svg

    Left: when 2 J-coupling constants are sufficiently unequal (Jab>Jbc) for spin ½ nuclei, a doublet of doublets with an intensity ratio of about 1:1:1:1 is seen in NMR spectra. Right: when Jab=Jbc for spin ½ nuclei, a triplet (collapsed or overlapping doublet of doublets) with an intensity ratio of about 1:2:1 is always seen in NMR spectra.

  6. Phosphorus-31 nuclear magnetic resonance - Wikipedia

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

    Phosphorus-31 NMR spectroscopy is an analytical chemistry technique that uses nuclear magnetic resonance (NMR) to study chemical compounds that contain phosphorus. Phosphorus is commonly found in organic compounds and coordination complexes (as phosphines ), making it useful to measure 31 - NMR spectra routinely.

  7. Nuclear magnetic resonance decoupling - Wikipedia

    en.wikipedia.org/wiki/Nuclear_Magnetic_Resonance...

    Nuclear magnetic resonance decoupling (NMR decoupling for short) is a special method used in nuclear magnetic resonance (NMR) spectroscopy where a sample to be analyzed is irradiated at a certain frequency or frequency range to eliminate or partially the effect of coupling between certain nuclei. NMR coupling refers to the effect of nuclei on ...

  8. Fix problems signing into your AOL account - AOL Help

    help.aol.com/articles/help-signing-in

    Use the Sign-in Helper to locate your username and regain access to your account by entering your recovery mobile number or alternate email address.; To manage and recover your account if you forget your password or username, make sure you have access to the recovery phone number or alternate email address you've added to your AOL account.

  9. Multiplicity (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Multiplicity_(chemistry)

    For example, the ground state of a carbon atom is 3 P (Term symbol). The superscript three (read as triplet) indicates that the multiplicity 2S+1 = 3, so that the total spin S = 1. This spin is due to two unpaired electrons, as a result of Hund's rule which favors the single filling of degenerate orbitals. The triplet consists of three states ...