1. NMR Chapter 13 13 C-NMR Spectroscopy CHEMISTRY 220 Spring 2003

2. Deuterated Solvents Deuterium ( 2 H) has a spin quantum No. of 1. No. of spin states = 2 I + 1 = 3 Deuterium does couple to 13 C nuclei. Chloroform-d 1 : (1:1:1)

3. Acetone in Chloroform-d 1 Methyl carbons Carbonyl carbon CDCl 3 carbon

4. Deuterated Solvents Deuterium ( 2 H) has a spin quantum No. of 1. Does not couple to protons ( 1 H) for reasons that are beyond the scope of this course. Multiplicity follows 2nI+1 rule. DMSO-d 6 Acetone-d 6, and Methanol-d 4 display a septet. Cyclohexane-d 12 displays a pentet.

5. General Chemical Shift Regions

6. 2-Butanone (MEK) abc d Methanol-d 6 This is the form of a typical carbon spectrum – it is proton noise decoupled (see single lines for all carbons)

7. Off-Resonance Decoupling (2nI+1) a b c

8. DEPT Experiment Distortioless Enhancement by Polarization Transfer Distinguishes 1 o, 2 o, 3 o, 4 o carbons! Several different types of DEPT experiments Page 488-9 of your text shows two kinds The ACDLabs® Software that you will use in lab has a different kind – this is the one that I want you to learn!

9. DEPT from ACDLabs® Prediction Software In this experiment: The CH 3 and CH carbons are negative The CH 2 and CH carbons are positive a d c b

10. Isopropyl Butanoate a b c a b c c e f d d ef

11. p-methyl benzoic acid a b cd f e