NMR

Question 1

what would account for a doublet in H NMR?

Answer 1

a group adjacent to a CH splitting = (n+1)

Question 2

How does 31P affect NMR?

Answer 2

has the same affect as a H, each P attached to a group splits it

e.g. CH attached to P on one side and P on the other, will be split into a doublet of doublets as for CH n=1 (n+1) = 2 = doublet

the 2 P split it into two doublets (doublet of doublets = 4 peaks)

Question 3

What does the number of environments tell you? i.e. 2 P environments

Answer 3

there are 2 P in the structure separately

Question 4

what does P being deshielded mean?

Answer 4

it has a higher chemical shift so must be attached to an EWG such as oxygen, NO2, CHO, COOH, CN,

Question 5

how many bonds does P make?

Answer 5

can be either 3 or 5, often found attached to Ph groups

Question 6

what is a ddq?

Answer 6

doublet of doublet of quartets = 2x2 = 4
4x4 = 16 peaks

Question 7

What is the result of H coupled to P?

Answer 7

doublet

Question 8

What is the result of P coupled to 3Me?

Answer 8

3Me = 3CH3 = 9H

9+1 = dectet

Question 9

What does it mean if two J couplings are the same for separate peaks?

Answer 9

they are coupled/next to each other

Question 10

For fluorine NMR what may a triplet represent?

Answer 10

an F next to CH2

Question 11

what is P{H}

Answer 11

P NMR decoupled to H (so no splitting by H observed)