1 / 29

Principles and Applications of NMR Spectroscopy

Principles and Applications of NMR Spectroscopy Instructor: Tai-huang Huang ( bmthh@ibms.sinica.edu.tw ), (02) 2652-3036 http://www.nmr.sinica.edu.tw/~thh/lecture.html Time:  Tuesday and/or Friday 2-5 PM

atara
Download Presentation

Principles and Applications of NMR Spectroscopy

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. Principles and Applications of NMR Spectroscopy Instructor: Tai-huang Huang (bmthh@ibms.sinica.edu.tw), (02) 2652-3036 http://www.nmr.sinica.edu.tw/~thh/lecture.html Time:  Tuesday and/or Friday 2-5 PM (9/21, 10/5, 10/8, 10/12, 10/15, 10/22, 10/26, 10/29, 11/2, 11/9, 11/12, 11/16, 11/19, 11/30, 12/7) Place: Rm. N617, IBMS, Academia Sinica Textbooks: 1. Lecture by James Keeler on “Understanding NMR spectroscopy” (http://www-keeler.ch.cam.ac.uk/lectures/) 2. Rules, G.S. and Hitchens, T.K. “Fundamentals of Protein NMR spectroscopy” 3. Cavanagh, Fairbrother, Palmer, and Skelton: “Protein NMR spectroscopy – Principles and practice” Academic press, 1996. 4. Selected review articles.

  2. Curse Content • This will be a comprehensive lecture course, focusing on modern high field • NMR spectroscopy in solution, with applications to protein structure, dynamics • and functional studies. Topics to be covered include: • Basic NMR theory, including quantum mechanical and vectorial descriptions  • of NMR spectroscopy. • 2. Basic experimental aspects of NMR: NMR data acquisition and processing. • 3. Product operator formalism analysis of pulse programs. • 3. Spin dynamics: Coherent selection, phase cycling, gradient enhanced • spectroscopy. • 4. Heteronuclear multidimensional NMR spectroscopy. • 5. Relaxation and protein dynamics. • 6. Special topics: TROSY, RDC, PRE and reduced dimensionality etc. • 7. Applications to protein NMR in solution.

  3. Course Outline • Lect #DateTopics • 1 9/21 NMR and Energy level • 2 10/5 Vector Model • 3 10/8 Fourier Transform and Data processing • 4 10/12 How the spectrometer works • 5 10/15 Product Operator • 6 10/22 • 7 10/26 Two dimensional NMR • 8 10/29 • 9 11/2 Coherence selection and phase cycling • 10 11/5 • 11 11/9 Relaxation • 12 11/12 Selective topics • 13 11/16 Selective topics • 14 11/19 Selective topics • 15 11/30 Selective topics • 16 12/7 Selective topics

  4. NMR Historic Review

  5. 2002 Nobel prize in Chemistry was awarded to Kurt Wuthrich NMR is a versatile tool and it has applications in wide varieties of subjects in addition to its chemical and biomedical applications, including material and quantum computing.

  6. Edward M. Purcell 1952, Physics Kurt Wuthrich 2002, Chemistry Richard R. Ernst 1992, Chemistry Isador I. Rabi 1944, Physics Paul Lauterbur 2003, Medicine Peter Mansfield 2003, Medicine Felix Bloch 1952, Physics

  7. CW NMR 40MHz (1960)

  8. Dominant interactions:H = HZ + HD + HS + HQ.HZ = Zeeman Interaction HD = Dipolar Interactions HS = Chemical Shielding Interaction. HQ = Quadrupolar Interaction 6 Electrons Basic Nuclear Spin Interactions 3 3 Nuclear Spin j Ho Ho Nuclear Spin i 1 2 1 5 4 4 Phonons 4

  9. z x Mo x Mxy B1 y a y wo Lecture 2: Vector Model Bulk Magnetization: The sum of all magnetic moments (1020 spins) Larmor frequency: o = Bo (rad·S-1); or  = Bo /2 (Hz) Pulse Detection: a deg pulse 90 deg pulse Z Mo  Signal: Y ot X Mosin

  10. Effect of external magnetic field:

  11.  Collecting NMR signals • The detection of NMR signal is on the xy plane. The oscillation of Mxy generate a current in a coil , which is the NMR signal. • Due to the “relaxation process”, the time dependent spectrum of nuclei can be obtained. This time dependent spectrum is called “free induction decay” (FID) Mxy time (if there’s no relaxation ) (the real case with T1 &T2) time

  12. Rotating frame: A reference frame which rotate with respect to the Z-axis of the laboratory frame at frequency rot Z Mo • Lamor frequency in the rotating frame:  = o - Rot = B then B =  /  = Bo - Rot/ For Rot = o B = 0  Bo Y ot X Mosin Rot/ In the rotating frame with rot = othe signal one observe is Mosin (No oscilation) and B = 0 Effective field: In the presence of RF-field (Radio frequency) B1 the total field: Static frame: B = Bo + B1 Rotating frame: Beff = B + B1 Tilt angle: M will rotate about Beff at a rate of eef = Beff

  13. Effective field in frequency unit: Z Mo • On resonance pulse: rot = o and  = 0 • eff = 1(The magnetization will rotate w.r.t. the B1 axis by an angle, (the flipping angle)  = 1  = o o pulse (90o, 180o pulse) 180o pulse is also called the “inversion pulse”  Bo Y B1 ot X Mosin Rot/ For arbitrary angle :

  14. Hard pulse:If B1 >> B the effectiv field lies along B1 and all resonances appeared to be on resonance. Example: Is P(90o) = 12 us pulse a hard pulse forB = 10 ppm in 500 MHz spectrometer ?  = 90o = /2 = B1 x12X10-6 1 = B1 = /24x106 1 = /2 = 20.8 kHz B = 10 ppm/2 = 5x500 = 2.5 kHz << 1 Ans: Yes, it is a hard pulse. Detection in the rotating frame : mHz rot Transmitter Probe o mHz rot rot - rot Digitizer Computer Receiver mHz kHz Basic pulse acquiring scheme : More than one resonance:

  15. Pulse calibration: Spin Echo :

  16. Z Pulses of different phases: Y X Y-pulse (90y) X-pulse (90X or 90) Relaxation (Inversion recovery expt):

  17. NMR Relaxation

  18.  = o - rot = the offset frequency 90% 1.6 • To record a 200 ppm 13C spectrum at 600 MHz spectrometer: • = 200 ppm x 150 = 3o kHz; 1 = /1.6 = 30000/1.6 =18,750 Hz = ? Gauss ?  P(90) = ? Us for 13C ?

  19. Selective excitation of a range of resonances:

  20. Selective inversion (Soft pulse): Shaped pulses are designed to affect only the resonances of interest

More Related