1 / 8

Nuclear Magnetic Resonance

Nuclear Magnetic Resonance. Relaxation and In-homogeneities. ANIMATED ILLUSTRATIONS. WONDERSHARE PPT to WMV conversion Software. MS Powerpoint Presentation Files. Uses Animation Schemes as available in MS XP or MS 2003 versions. A class room educational material.

loreleic
Télécharger la présentation

Nuclear Magnetic Resonance

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nuclear Magnetic Resonance Relaxation and In-homogeneities ANIMATED ILLUSTRATIONS WONDERSHARE PPT to WMVconversion Software MS Powerpoint Presentation Files Uses Animation Schemesas available in MS XP or MS 2003 versions A class room educational material http://ugc-inno-nehu.com/links_from_web.html N.M.R. Spectroscopy Illustrated. Examples of Spectra from SDBS Spectral data base. Dr. S. Aravamudhan

  2. Single line NMR spectrum 0 ppm TMS 10ppm A definition: Magnetic Resonance Phenomenon is a manifestation due to the presence of INTRINSIC SPIN angular momentum and the associated Magnetic Moment characteristically in electrons and Nuclei When the experimental conditions are set for the NUCLEI to resonate, then it is the Nuclear Magnetic Resonance. NMR spectrum of a sample of spin ensemble…….. PMR spectrum

  3. Even before applying magnetic field electrons are in constant circulation in atoms and molecules protons electrons The application of the external field can alter the motional characteristics of the atomic molecular electrons. Thus the precessional frequency when placed in the electronic surrounding would not be the same for the nucleus as it is in a bare nucleus. These can give rise to magnetic moments and fields at the atomic nuclei and such orbital magnetic moments and their interaction with spin magnetic moments are the ones which are studied under the topic of SPIN-ORBIT couplings, Lande g-factor, effective moments and so on.. At this juncture these would be granted as what happens in the absence of magnetic field; and consider only the additional consequences due to theapplication of external magnetic fields. SPIN angular momentum & Magnetic Moments A reference molecule (TMS) is also placed along with the test molecule in the sample. The changes in the test molecule with reference to (the differences from the reference) are termed as “chemical shifts”. On application of external magnetic field, nuclei start precessing chemical shifts.

  4. A B SPIN-SPIN Interaction Dipole-Dipole interaction Through space protons electrons Not encountered in solution spectra C, P, N, H j θij rij i Electron pair shared J x (I1 •I2 ) J coupling constant expressed in Hz CONTACT Interaction Through bond Scalar interaction

  5. 2nI+1 and with I=1/2 2-spins cause a line to split into 3 lines 3-Spins cause a line to split into 4 lines

  6. Ethyl benzene

  7. Ethyl benzene

More Related