15E.8 Flashcards

1
Q

what are the two features that 1H NMR LR AND 1H NMR HR agree own

A
  1. peaks at different chemical shifts help identify the different chemical environments of hydrogen atoms
  2. the relative peak areas (the ratio of peak area) help us decide the number of hydrogen atoms responsible for the peak
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2
Q

what are equivalent protons

A

they are hydrogen atoms on the same chemical environment

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3
Q

what is the extra feature that 1H NMR HR has that 1H NMR LT doesn’t have

A

a splitting pattern

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4
Q

what is a splitting pattern

A

it is the appearance of a peak as a small number of small sub-peaks that are very close to each other

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5
Q

for splitting pattern the chemical shift

A

located in the centre of the group of sub-peaks

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6
Q

the relative area of 1H NMR HR is shown by

A

an integration trace, or by showing the number next to the peaks

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7
Q

the relative area indicates

A

the ratio of the number of protons, so its not always the real value

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8
Q

what causes the splitting of the peaks

A

the influence that comes form the protons (hydrogen atoms) attached to the adjacent carbon

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9
Q

the splitting of the peaks is referred to as

A

(spin-spin coupling)

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10
Q

what is the n + 1 rule

A

if a carbon has n protons, then the peaks on the adjacent carbon will be split into n + 1 sub-peaks (multiples)

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11
Q

what are multiples

A

the different splitting patterns observed (singlets, doublets, triplets. quartets) in a HR 1H NMR spectrum

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12
Q

if a peak is not split it is called a

A

singlet

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13
Q

if a peak is split to two sub peaks it is called

A

doublet

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14
Q

if a peak is split into 3 sub peaks its called

A

triplet

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15
Q

if a peak is split into 4 sub peaks it is called

A

quartet

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16
Q

what are the shapes of multiples

A

table A page 151

17
Q

the splitting of a group of protons only indicate

A

the number of protons on the adjacent carbon, and noting about the group of protons being split

18
Q

analysis of the spectrum of butanone

A

page 151 table B

19
Q

a molecule that is completely symmetrical doesn’t have a

A

splitting pattern that is because neither carbon group would effect each other since they are equivalent

20
Q

when a peak is split to 5 sub-peaks we call it

A

a quintet

21
Q

when a peak is split to 6 sub-peaks we call it

A

sextet

22
Q

if a proton is attached to two different adjacent protons what would the effect be on it

A