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Core - Analytical Chemistry

    Chapter 7

    Principles of Nuclear Magnetic Resonance

    7.1 : Nuclear Magnetic Resonance (NMR): Overview01:07

    7.1 : Nuclear Magnetic Resonance (NMR): Overview

    Nuclear magnetic resonance (NMR) is a phenomenon exhibited by certain nuclei that can absorb characteristic radio frequency radiation under certain ...

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    7.2 : Atomic Nuclei: Nuclear Spin01:08

    7.2 : Atomic Nuclei: Nuclear Spin

    All atomic particles possess an intrinsic angular momentum, or 'spin'. Electrons, protons, and neutrons each have a spin value of ½, although ...

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    7.3 : Atomic Nuclei: Nuclear Magnetic Moment00:59

    7.3 : Atomic Nuclei: Nuclear Magnetic Moment

    All atomic nuclei are positively charged. When they have a nonzero spin, they behave like rotating charges. As a consequence of their charge and spin, ...

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    7.4 : Atomic Nuclei: Nuclear Spin State Overview01:03

    7.4 : Atomic Nuclei: Nuclear Spin State Overview

    NMR-active nuclei have energy levels called 'spin states' that are associated with the orientations of their nuclear magnetic moments. In the ...

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    7.5 : Atomic Nuclei: Nuclear Spin State Population Distribution01:14

    7.5 : Atomic Nuclei: Nuclear Spin State Population Distribution

    Near absolute zero temperatures, in the presence of a magnetic field, the majority of nuclei prefer the lower energy spin-up state to the higher energy ...

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    7.6 : Atomic Nuclei: Larmor Precession Frequency01:11

    7.6 : Atomic Nuclei: Larmor Precession Frequency

    The earth's gravitational field produces a 'twisting force' perpendicular to the angular momentum of a spinning mass (such as a spinning top) ...

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    7.7 : Atomic Nuclei: Magnetic Resonance01:05

    7.7 : Atomic Nuclei: Magnetic Resonance

    The number of nuclear spins aligned in the lower energy state is slightly greater than those in the higher energy state. In the presence of an external ...

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    7.8 : Atomic Nuclei: Nuclear Relaxation Processes01:23

    7.8 : Atomic Nuclei: Nuclear Relaxation Processes

    In the absence of an external magnetic field, nuclear spin states are degenerate and randomly oriented. When a magnetic field is applied, the spins begin ...

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    7.9 : Atomic Nuclei: Types of Nuclear Relaxation01:28

    7.9 : Atomic Nuclei: Types of Nuclear Relaxation

    Relaxation in NMR systems is a first-order exponential decay and can occur by either spin–lattice or spin–spin mechanisms. Spin–lattice ...

    260 views
    7.10 : NMR Spectrometers: Overview01:20

    7.10 : NMR Spectrometers: Overview

    NMR spectrometers consist of a strong magnet, a radiofrequency transmitter, and a detector attached to a computer console for recording spectra of samples ...

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    7.11 : NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences01:17

    7.11 : NMR Spectrometers: Radiofrequency Pulses and Pulse Sequences

    A pulse is a short burst of radio waves distributed over a range of frequencies that simultaneously excites all the nuclei in the sample. Upon passing a ...

    762 views
    7.12 : NMR Spectrometers: Resolution and Error Correction01:14

    7.12 : NMR Spectrometers: Resolution and Error Correction

    When magnetic nuclei in a sample achieve resonance and undergo relaxation, the signal detected in NMR is an approximately exponential free induction ...

    672 views
    7.13 : Diamagnetic Shielding of Nuclei: Local Diamagnetic Current01:14

    7.13 : Diamagnetic Shielding of Nuclei: Local Diamagnetic Current

    An applied magnetic field causes the electrons present in the molecule to circulate, setting up a local diamagnetic current within the molecule. The local ...

    839 views
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