OC5: NMR spectroscopy

Question 1

nuclear magnetic resonance spec.

Answer 1

measures absorption at different frequencies, allowing for identification of elements and structure

Question 2

downfield

Answer 2

moving to the left of an NMR spectrum (higher chemical shift)

Question 3

upfield

Answer 3

moving to the right of the NMR spectrum (lower chemical shift)

Question 4

deshielding

Answer 4

when electron-withdrawing groups pull electrons away from the core of an atom, making it more susceptible to the magnetic field

Question 5

shielding

Answer 5

when electron-donating groups increase the electron density near the core of an atom, reducing its susceptibility to the magnetic field

Question 6

H-NMR spectroscopy

Answer 6

certain types of bonded protons (in the form of hydrogen atoms) cause a specific chemical shift

Question 7

sp3 carbon

Answer 7

0-2 ppm

Question 8

sp carbon

Answer 8

2-3 ppm

Question 9

sp2 carbon

Answer 9

3-6 ppm

Question 10

aromatic carbon

Answer 10

6-9 ppm

Question 11

aldehyde

Answer 11

9-10 ppm

Question 12

carboxylic acid

Answer 12

10-13 ppm

Question 13

coupling (spin-spin splitting)

Answer 13

occurs when hydrogen atoms attached to adjacent carbons interfere with one another’s magnetic environment

Question 14

doublet

Answer 14

two subpeaks

Question 15

triplet

Answer 15

three subpeaks