15E.8 Flashcards
what are the two features that 1H NMR LR AND 1H NMR HR agree own
- peaks at different chemical shifts help identify the different chemical environments of hydrogen atoms
- the relative peak areas (the ratio of peak area) help us decide the number of hydrogen atoms responsible for the peak
what are equivalent protons
they are hydrogen atoms on the same chemical environment
what is the extra feature that 1H NMR HR has that 1H NMR LT doesn’t have
a splitting pattern
what is a splitting pattern
it is the appearance of a peak as a small number of small sub-peaks that are very close to each other
for splitting pattern the chemical shift
located in the centre of the group of sub-peaks
the relative area of 1H NMR HR is shown by
an integration trace, or by showing the number next to the peaks
the relative area indicates
the ratio of the number of protons, so its not always the real value
what causes the splitting of the peaks
the influence that comes form the protons (hydrogen atoms) attached to the adjacent carbon
the splitting of the peaks is referred to as
(spin-spin coupling)
what is the n + 1 rule
if a carbon has n protons, then the peaks on the adjacent carbon will be split into n + 1 sub-peaks (multiples)
what are multiples
the different splitting patterns observed (singlets, doublets, triplets. quartets) in a HR 1H NMR spectrum
if a peak is not split it is called a
singlet
if a peak is split to two sub peaks it is called
doublet
if a peak is split into 3 sub peaks its called
triplet
if a peak is split into 4 sub peaks it is called
quartet
what are the shapes of multiples
table A page 151
the splitting of a group of protons only indicate
the number of protons on the adjacent carbon, and noting about the group of protons being split
analysis of the spectrum of butanone
page 151 table B
a molecule that is completely symmetrical doesn’t have a
splitting pattern that is because neither carbon group would effect each other since they are equivalent
when a peak is split to 5 sub-peaks we call it
a quintet
when a peak is split to 6 sub-peaks we call it
sextet
if a proton is attached to two different adjacent protons what would the effect be on it
