1. Lecture 1 Zhenming (Jimmy) Du
GSU Chem 4050/6050
Lecture 1
Zhenming (Jimmy) Du

2. Round Robin Instructor: Dr. Zhenming (Jimmy) Du NSC 134A
Phone:
Website: sites.gsu.edu/zdu
Students:

3. Scope of Chem 4050/6050: Level I Chem 4050/6050.
Introduction to Fourier-Transform NMR Spectroscopy. Prerequisites: demonstrated research need and approval of the departmental chair. Introduction to techniques of Fourier-Transform Nuclear Magnetic Resonance Spectroscopy

4. Next step: Level II Fall Semester
Chem 8450, NMR Spectroscopy (4) Prerequisite:  Chem 6050 or consent of the instructor.  Theory and application of NMR spectroscopy for the characterization and elucidation of organic and biological molecules.

5. Next step: Level III Spring semester:
Chem Biomolecular Nuclear Magnetic Resonance. (3) Prerequisite: Introductory courses in spectroscopy, such as Chem 4050/6050 and Chem 4190/6190 or equivalent. Some experience in the application of quantum mechanics in spectroscopy is useful, but not essential. Experimental design and interpretation of nuclear magnet resonance data, particulary with respect to applications in structural biology.

6. Textbook required Edition: 2nd ISBN-13: 978-0198703419

7. Helpful Books
This text is aimed at people who have some familiarity with high-resolution NMR and who wish to deepen their understanding of how NMR experiments actually ‘work’. This revised and updated edition takes the same approach as the highly-acclaimed first edition. The text concentrates on the description of commonly-used experiments and explains in detail the theory behind how such experiments work. The quantum mechanical tools needed to analyse pulse sequences are introduced set by step, but the approach is relatively informal with the emphasis on obtaining a good understanding of how the experiments actually work. The use of two-colour printing and a new larger format improves the readability of the text. 

8. Helpful Books
This work-book will guide you safely, in step-by-step descriptions, through every detail of the NMR experiments within, beginning with 1D routine experiments and ending with a series of advanced 3D experiments on a protein:

9. Topics today NMR Basics: Theory for NMR detection;
Concerns during NMR detection.
Reading assignment:
Lecture 1 notes;
Chapter 1 & 2;
Read gsuNMR guide before lab 1;
Reading NMR operation procedures before lab 1.

10. 1. What is NMR?
NMR =
Nuclear
Magnetic
Resonance

11. About MRI
(N)MRI =
(Nuclear)
Magnetic
Resonance
Imaging

12. NMR Applications

13. NMR Applications

14. Organic Structure Illustration:Heparin
Proton NMR profiles: (a) Oversulfated heparan sulfate. (b) 30% oversulfated heparan sulfate + 70% heparin. (c) Heparin. (d) Contaminated heparin lot , which had both oversulfated heparan sulfate and 5% galactosamine-containing GAGs that were undetectable by NMR. (e) Oversulfated heparin by-product. (f) A mixture of 50% oversulfated heparin by-product and 50% heparin. (g) Contaminated heparin lot OSHS, heparin oversulfated by chemical sulfation; OSDS, dermatan oversulfated by chemical sulfation; OSCS, chondroitin oversulfated by chemical sulfation; *, oversulfated heparan sulfate.

15. Protein Structure Illustration
2LCJ
CFPGDTRILVQIDGVPQKITLRELYELFEDERYENMVYVRKKPKREIKVYSIDLETGKVVLTDIEDVIKAPATDHLIRFELEDGRSFETTVDHPVLVYENGRFIEKRAFEVKEGDKVLVSELELVEQSSSSQDNPKNENLGSPEHDQLLEIKNIKYVRANDDFVFSLNAKKYHNVIINENIVTHQ
Du, Z.,  Liu, J.,  Albracht, C.D.,  Hsu, A.,  Chen, W.,  Marieni, M.D.,  Colelli, K.M.,  Williams, J.E.,  Reitter, J.N.,  Mills, K.V.,  Wang, C.
Journal: (2011) J.Biol.Chem. 286:

16. Nuclear=?
Atoms are made of electrons and nuclei. Each atomic nucleus has four important physical properties: mass, electric charge, magnetism, and spin. Mass, electric charge: more sensible Nuclear magnetism and spin: less tangible ( but need to understand here)

17. Quantum mechanics treatment
Nucleus have four quantum numbers(n,l,ms,s) n: Principle quantum number(n): the size of the orbital (1,2,3,…,n) l: Angular quantum number (l): the shape of the orbital (0, 1, …, n-1)(s,p,d,f,…) ms: Magnetic quantum number(m):orientation in space of a particular orbital [-l, …,-2,-1,0,1,2,…,l] s: Nucleus has an intrinsic spin angular momentum ( hence spin quantum number, I).

18. Nuclear Spin Some nuclei possess an intrinsic angular momentum
Nuclear spin angular momentum is quantized in integer multiples of h/2π(or h is Planck’s constant)
Maximum observable component p of nuclear spin angular momentum is p= I * h/2 π
I = nuclear spin quantum number
I varies as a result of the interactions between protons and neutrons

19. Nuclear spin differs from electron spin both quantized, I ≠ 0: Nmrable

20. Nuclear spin differs from electron spin both quantized, I ≠ 0: Nmrable
Nuclide
12C
16O
1/2 1H
13C
15N
19F
29Si, 31P 1 2H
14N
3/2
11B
23Na
35Cl
37Cl
5/2
17O
27Al 3
10B

23. Example:
ν = γ * B0/ 2π
For proton , γ = * rad T-1 S-1
For carbon, γ = 6.73 * rad T-1 S-1
T: Telsa = 10,000 Gauss
B0= 9.40T, corresponds to 400MHz NMR for proton.
corresponds to NMR for carbon.
B0= 11.45T, corresponds to NMR;
Bo = , corresponds to MHz NMR;
Commercially available magnetic field 1.4T T
60MHz-1GHz
This lies on the radiofrequency range (RF) of the electromagnetic spectrum.

24. Resonance along is not enough
Detecting the resonance is the key!

26. Low energy range!
Radio frequency range!

27. At room temp, the number of spins in the lower energy level (N+)is slightly greater than the number in the upper level (N-).

28. The Boltzmann Factor and Partition Functions
The Boltzmann factor tells us that if a system has states with energies E1, E2, E3,. …, the probability Pj that the system will be in the state with energy Ej depends exponentially on the energy of that state, or
Pj ∝ 𝑒 −𝐸𝑖/𝐾𝑏𝑡
At room temp, the number of spins in the lower energy level (N+)is slightly greater than the number in the upper level (N-).

30. NMR Detection Key Elements
A strong magnetic field;
RF pulse to excite nuclei in the sample;
Detection of the feedback (NMR signal).

31. A strong magnetic field;
Superconducting solenoid;

32. 2. RF pulse
Δ𝐸=ℎ𝑣=γ ℏ𝐵 0
Twist between 𝑣 and 𝐵 0 to achieve balance;
For protons, if you supply a magnetic field B0, then all protons will appear in the same frequency 𝑣 as γ 𝑎𝑛𝑑 ℏ 𝑎𝑟𝑒 𝑎𝑙𝑙 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡𝑠?.

33. • 1926 Pauli’s prediction of nuclear spin!
Two or more identical fermions cannot occupy the same quantum state within a quantum system simultaneously.
It is impossible for two electrons to have the same values of the four quantum numbers: n, ℓ, angular momentum quantum number, mℓ, the magnetic quantum number, and ms, the spin quantum number.

34. • 1932 Detection of nuclear magnetic
moment by Stern using molecular
beam!

35. – 1936 First theoretical prediction of NMR
by Gorter; his attempt to detect the
first NMR did not work (LiF
&K[Al(SO4)2]12H2O) at low temp.

36. – 1938 Isidor Rabi discovered NMR.

37. • 1945 First NMR of solution (Bloch et al
for H2O) and solids (Purcell et al for
parafin)!

41. • 1949 Discovery of chemical shifts!

43. 2014 Varian is gone after 50 years.

44. 2014 Varian is gone after 50 years.

45. 2014 Varian is gone after 50 years.

46. 2014 Varian is gone after 50 years.

47. Relative sensitivity S/N ∝ γ3 Absolute Sensitivity S/N ∝ γ3 * C
NMR Sensitivity.
Relative sensitivity S/N ∝ γ3
Absolute Sensitivity S/N ∝ γ3 * C
C stands for natural abundance.

50. Pulse NMR is fast 20ppm at 400MHz= 8000Hz, 125us for 360 pulse

51. What about a spectrum between 40ppm and -10 ppm?
Exercises
Now you are running NMR on 500Mhz NMR, and you found your 90 pulse for proton is 12 μs long. Your lab mate told you he has peaks that appears between 5 ppm and 0 ppm. Is the pulse strong enough to cover that range?
What about a spectrum between 40ppm and -10 ppm?

52. RF Pulses

54. 3. Chemical Shift Earth’s magnetic field 0.6 Gauss at equator
Refrigerator magnet Gauss
MRI medical scanners Tesla (3 - 15,000 G)
High field NMR magnet
200 MHz Tesla (47,000 G)
400 MHz Tesla (94,000 G)
500 MHz Tesla (117,000 G)
800 MHz Tesla (181,000 G)

55. Proton peaks are isolated

56. Chemical Shift 𝐵 𝑙𝑜𝑐 = 𝐵 0 (1-σ)
More electron, less Bloc, smaller frequency.

57. Chemical Shift

58. Chemical Shift

59. Chemical Shift CH4 CH3Cl CH2Cl2 CHCl3 δ=0.23 δ=3.05 δ=5.33 δ=7.26 CH3I
CH3Br
CH3F
δ=2.16
δ=2.68
3.05
4.26

60. Chemical Shift

61. Chemical Shift

62. Advantage of FT-NMR vs. CW
Faster speed. No sweeping needed. 1 s/ scan vs. 4500s / scan
Multiple scan to improve S/N;
Spin Manipulation for complicated NMR experiments, such as water suppression, NOESY, and HMBC.