Proton (H) NMR

Question 1

What does NMR spectroscopy stand for?

Answer 1

Nuclear Magnetic Resonance

Oscopy is measuring the difference of energy between a high and low state

Question 2

What does NMR tell you?

Answer 2

Will tell you the electron environment around H
Shows hydrogen neighbours
Defines the number of H’s in a signal

Question 3

What does the M is NMR stand for?

Answer 3

External. Snaps the spin states to parallel or anti parallel. Moving with the flow (parallel) is lower energy (alpha). Moving against the flow (anti parallel) is higher energy (beta)

Question 4

What’s does the R stand for in NMR?

Answer 4

Resonance. Alpha flips to beta and beta flips to alpha.

Question 5

What are the labels on the NMR Spectrum?

Answer 5

Vertical = abundance 
Horizontal = ppm & resonance frequency

Question 6

What nucleis do you see NMR

Answer 6

1H, 13C (See 90% of the time)

19F, 31P, 7O (barely see)

Question 7

What is electron poor and electron rich?

Answer 7

Downfield (left) is electron poor. Up field (right) is electron rich

Question 8

What is the scale of NMR?

Answer 8

0-14

Question 9

What is at 12-14

Answer 9

Carboxillic H (most e- poor) O=C-O-H

Question 10

What’s at 10-9?

Answer 10

Aldehydes (electron poor) O=C-H

Question 11

What is at 6-5?

Answer 11

Alkene C=C

Question 12

What is at 4-3?

Answer 12

Othoxy group. H-C-O

Question 13

What is at 2?

Answer 13

Ketonics H-C-C=O

Question 14

What is at 1?

Answer 14

Alkane (super electron rich) H-C-CH2

Question 15

What is around 7.26ppm?

Answer 15

Chloroform
Iodoform
Bromoform
Fluroform

Question 16

What are the integration values used for?

Answer 16

To account for all protons in the molecule. Divide the lowest area of each peak value by all values. If not a whole number multiply by a number to get a whole number so when everything is added up it squeaks the correct amount of protons

Question 17

What does the amount of peaks show you?

Answer 17

N+1. So three peaks means two neighbours. 1 peaks means zero neighbours

Question 18

What is at 11-12ppm

Answer 18

Phenolic H

Question 19

What is the coupling saying?

Answer 19

Same doesn’t couple with same. Different couples with different

Question 20

What is the J-value / J-constant?

Answer 20

A spin spin coupling constant. Measure the distance between the peaks.

Question 21

How many Hz is 3J, 2J, and 4J

Answer 21

3J = 7Hz
2J = 20Hz
4J = 1-2Hz

Question 22

If the molecule has symmetry how does it affect the signals?

Answer 22

H atoms that are the same on both sides have the same sigma

Question 23

How do you use IMP

Answer 23

Only use on proton NMR. Use to interpret NMR.
Integration - count how many protons
Multiplicity - look at neighbours
PPM Value - look at position (ppm)

Question 24

The bigger the J…

Answer 24

The smaller the Hz

Question 25

What does 1J show?

Answer 25

C-H

Question 26

What does 5J mean?

Answer 26

Benzene

Question 27

How to calculate J Values?

Answer 27

Cross multiply the difference between 0 and 1 in units and Hz and then the space between the peaks.

Question 28

What does the N in NMR stand for?

Answer 28

Nuclear. Dipole moments. What the molecules split