How does NMRWork
indicates where hydrogenscan befound
findsstructures oforganiccompounds
how are in eachenvironment
many hydrogens
when isotopes are placed in a magneticfield the magnetic
field
produced
nucleusbecome aligned with or theexternalmagneticfield
by against
Allignedwithfield
Strongexternal
fieldapplied
magnetic
alligned against
Evel field field
Whenlined
upwiththefield thenucleus is at lowerenergythanwhenlinedup againstfield
allignedagainst
produceon electrical signal
energygap
allignedwith
lowerenergy
Theisotopecan emit radiation electrical signal returnstobeingalignedwiththe
appliedmagnetic
field
called flipping or resonance
The energy difference betweenthealligned I non allignedstate thenucleus
depends on the environment of
, Chemical
Shift electronegativity
An NMRspectrum shows chemical shiftegg
1 4 1 of
group compounds where
oneor more te atoms are
12 it 4 to replaced
by 2M deuterium
ppm doesn'tinterfere
shorum
Spectrum isobtained dissolving thetestcompound in a deuteratedsolvent
by
adding a few drops TMSof tetraChloromethane CCL
TMS is partofsampleundergoinganalysis l acts as a control baseline
Partimonthis PeakingFran it's
Siccris
CHz Si Ch
shift the position an NMRpeakrelative to
Chemical kHz
the TMS
of
Standard it
is the extent which to
other H signals differfrom TMS signal position
Why is TMSused as theinternalstandard
1 All 12 H atoms are chemically equilivant produce a singleintensepeak
2 inert doesn'treactwiththe compounds beinganalysed
3 Signal is wellseparatedfromthe signals produced byother organic compounds
4 It is miscible withthesolventused in NMRsamples organic samples
Whydo different Hatoms protons absorb at differentvalues
e feels magnetic
Moe 8 makefrom magenta
field more
indicates where hydrogenscan befound
findsstructures oforganiccompounds
how are in eachenvironment
many hydrogens
when isotopes are placed in a magneticfield the magnetic
field
produced
nucleusbecome aligned with or theexternalmagneticfield
by against
Allignedwithfield
Strongexternal
fieldapplied
magnetic
alligned against
Evel field field
Whenlined
upwiththefield thenucleus is at lowerenergythanwhenlinedup againstfield
allignedagainst
produceon electrical signal
energygap
allignedwith
lowerenergy
Theisotopecan emit radiation electrical signal returnstobeingalignedwiththe
appliedmagnetic
field
called flipping or resonance
The energy difference betweenthealligned I non allignedstate thenucleus
depends on the environment of
, Chemical
Shift electronegativity
An NMRspectrum shows chemical shiftegg
1 4 1 of
group compounds where
oneor more te atoms are
12 it 4 to replaced
by 2M deuterium
ppm doesn'tinterfere
shorum
Spectrum isobtained dissolving thetestcompound in a deuteratedsolvent
by
adding a few drops TMSof tetraChloromethane CCL
TMS is partofsampleundergoinganalysis l acts as a control baseline
Partimonthis PeakingFran it's
Siccris
CHz Si Ch
shift the position an NMRpeakrelative to
Chemical kHz
the TMS
of
Standard it
is the extent which to
other H signals differfrom TMS signal position
Why is TMSused as theinternalstandard
1 All 12 H atoms are chemically equilivant produce a singleintensepeak
2 inert doesn'treactwiththe compounds beinganalysed
3 Signal is wellseparatedfromthe signals produced byother organic compounds
4 It is miscible withthesolventused in NMRsamples organic samples
Whydo different Hatoms protons absorb at differentvalues
e feels magnetic
Moe 8 makefrom magenta
field more
