Chemistry 344. Spectroscopy of Organic Compounds. Modern Spectroscopic Methods. Revolutionized the study of Organic Chemistry Determine the exact structure of small to medium size molecules in a few minutes.
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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
Spectroscopy of Organic Compounds
n = c/l
E = hn = hc/l
(where h = Plank’s constant)
examples: 1H and 13C.
examples: 2H and 14N.
examples: 12C and 16O.
and – ½ spin states.
d =distance from TMS (in hz)
radio frequency (in Mhz)
d 2.3 (6H, singlet)
d 7.0 (4H, singlet)
The Deshielding effect of an electronegative substituent can be seen in the NMR spectrum of 1-Bromobutane
Br – CH2-CH2-CH2-CH3
d (ppm): 3.4 1.8 1.5 0.9
No. of H’s: 2 2 2 3
Pattern Relative Peak Height
Doublet 1 : 1
Triplet 1 : 2 : 1
Quartet 1 : 3 : 3 : 1
Quintet 1 :4 : 6 : 4 : 1
If Ha is a set of equivalent hydrogens and Hx is an adjacent set of equivalent hydrogens which are not equivalent to Ha:
(d = 9-10 ppm) and coupling to alkyl H’s on adjacent carbon is small.
Synthesis of Ethyl Acetate by Fischer Esterification Results in an Equilibrium Mixture:
4.1(quart., 1H), 7.2-7.4 (m, 5H)
2.90 (trip., 4H), 7.1-7.3 (m, 4H)
4.38 (s, br, 1H), 4.52 (t, 1H),
7.2-7.4 (m, 5H)