H NMR Values

Make sure you put 'answer with finition' or it will be messed up

Middle of C chain

1.5-1.75

cyclopropane

0.25-0.5

amine (H-N) / alcohol

0.5-4.5 (could potentially appear anywhere)

amine-adjacent (H-C-N)

2.25-2.6

C chain attached to Ph

2.4-2.8

Ketone-adjacent

2-2.75

alkene-adjacent

1.8-2.25

How does being on a Me affect the shift?

-0.5

alkyne

1.75-2.75

amide-adjacent

3.25-3.6

ether

3.4-3.8

ester

4-4.5

CH₂Cl

3.6-4.1

alkene

4.5-6

Benzene

6-9

-methanoate (HCOO-)

8-8.4

aldehyde

9.4-10.5

water

1.25-1.75

Ar-NH₂

3.1-6

amide

5-12

-COOH

9-12.5

What would you use a ‘D₂O shake’ on?

Molecules with N-H or O-H as the H will be replaced with D so their signals will disappear due to different spin states. But any acidic protons will be replaced in a molecule.

Why might we see no coupling in N-H and O-H containing molecules?

• H bonding

• exchangeable H’s rapidly swap in solution

• protons they swap with are equally likely to be spin up or spin down

• any nearby protons just see an average of the 2 spin states

Common splitting pattern for alkynes

triplet

reason for common alkyne splitting

long range coupling