1. Kcal/mol 5.7 X 10 5 9.5 X 10 3 1.7 X 10 3 4.8 X 10 2 9.5 X 10 -3 1.27210 -4 EIMSNMR

2. To here! Nuclear Magnetic Resonance (NMR) Spectroscopy From here…

3. The Nobel Prize in Physics 1952 " for their development of new methods for nuclear magnetic precision measurements and discoveries in connection therewith " Felix BlochEdward Mills Purcell

4. Magnetic nuclei are in resonance with external magnetic field if they absorb energy and “spin-flip” from low energy state (parallel orientation) to high energy state (antiparallel orientation).

5. 5 atomic nuclei in absence of magnetic field atomic nuclei in presence of external magnetic field atomic nuclei can either align parallel (lower E) or antiparallel (higher E)

6. Magnetic nuclei are in resonance with external magnetic field if they absorb energy and “spin-flip” from low energy state (parallel orientation) to high energy state (antiparallel orientation).

7. Dependence of the difference in energy between lower and higher nuclear spin levels of the hydrogen atom

8. Nuclei in different environments (i.e. with different amounts of electron density around them) will require different amounts of energy to “flip” to higher energy different spin state

9. 9 Magnetic: o All nuclei with odd number of protons o All nuclei with odd number of neutrons Nonmagnetic: o Nuclei with even number of both protons and neutrons

10. Fig. 13-4, p. 444

11. 11

12. Really Old School: Continuous wave (CW) 40 MHz NMR spectrometer 1960

13. A little less old school: Continuous wave (CW) 60 MHz NMR spectrum 1964

14. Not quite so old school: 1980’s 60 MHz

15. The Nobel Prize in Chemistry 1991 "for his contributions to the development of the methodology of high resolution nuclear magnetic resonance (NMR) spectroscopy" Richard R. Ernst

16. 900 MHz NMR spectrometer Center for Biomolecular NMR, Heinrich-Heine-Universität Düsseldorf State-of-the-art

17. Colchitaxel, a coupled compound made from microtubule inhibitors colchicine and paclitaxel 17

18. Free-induction decay data and proton-decoupled 13C nuclear magnetic resonance spectra

19. Fig. 13-6, p. 447 13 C NMR spectrum 1-pentanol : 1 scan

20. Fig. 13-6, p. 447 13 C NMR spectrum 1-pentanol : 1 scan 13 C NMR spectrum 1-pentanol : 200 scans

21. The Nature of NMR Absorptions 1 H NMR spectrum 13 C NMR spectrum

22. The Nobel Prize in Chemistry 2002 "for his development of nuclear magnetic resonance spectroscopy for determining the three-dimensional structure of biological macromolecules in solution" Kurt Wüthrich

23. The Nobel Prize in Medicine 2003 " for their discoveries concerning magnetic resonance imaging " Paul C. Lauterbur Sir Peter Mansfield

24. More energy to flip nucleus Less energy to flip nucleus , ppm chemical shift

25. 25 Magnetically distinct 13 C NMR of methyl acetate Chemically equivalent nuclei always show the same absorption

26. 26 Magnetically distinct hydrogens and carbons!

27. Fig. 13-7, p. 448 77 ppm CDCl 3

28. Fig. 13-7, p. 448 77 ppm CDCl 3 sp3

29. 29

31. 31 For each molecule below: Determine the number of distinct carbon peaks Assign chemical shifts for each distinct carbon

32. Fig. 13-10a, p. 451

33. Information in a 1 H NMR spectrum 13 C NMR spectrum 1 H NMR spectrum

34. Table 13-2, p. 457

35. Table 13-3, p. 458

36. 6.5 – 8.0

37. 37 1 H NMR Integration Area under each peak is proportional to number of protons causing that peak. Gives ratio, not always exact number!

38. spin-spin splitting

39. Fig. 11-13, p. 424 Spin – Spin Splitting Absorption of a proton can split into multiple peaks (multiplet) Tiny magnetic field produced by one nucleus affects magnetic field felt by neighboring nuclei

40. Fig. 13-13, p. 460

41. 3.41303.41653.42703.4235  3.42 Chemical shift – middle of multiplet

42. Common NMR splitting patterns

43. Fig. 11-15, p. 425 C 3 H 7 Br

44. Fig. 11-15, p. 425 C 3 H 7 Br 12 2

45. Fig. 11-16, p. 427 1.5 1 11 C 10 H 12 O 2

46. C 10 H 12 O 333 4.5

47. Fig. 13-19, p. 466

51. p. 409