RMN 2D.ppt

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RMN Bidimensional
A RMN 2D fornece informações sobre conectividade e proximidade
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COSY spectroscopy (correlation spectroscopy)
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H - H COSY
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1H-1H COSY (Correlation Spectroscopy)
2-D NMR spectra have two frequency axes and one intensity axis, and it involve 1H-1H shift correlation; 
This will identify protons that are coupled (i.e., that split each other’s signal);
2-D dimensional plot with 1H spectrum along each axis and on the diagonal;
Protons coupling to one another produce off diagonal correlations
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Long range 
H - H COSY
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H C COSY
HSQC method
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COSY
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Measurement of CH coupling constants
 Heteronuclear J resolved Spectrum
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J Resolvido
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1H NMR
13C NMR
1
1
 3,7 2,6
 4,5 9,10,8
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2
4
5
OH
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9,10
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Nuclear Overhauser (NOESY) Spectrometry Proximity Through Space
A proton that is close in space to the irradiated proton is affected by the NOE whether or not it is coupled to the irradiated proton; if it is coupled, it remains at least partially coupled because the irradiation is week in comparison with that used for a decoupling experiment.
Can be a 1D or 2D NOESY technique
nOe is a through space effect
It has nothing to do with connectivity in the molecule
NOESY for very large molecules, ROESY for mid-size molecules
These spectra are used to locate protons that are close together in space
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Elucidation of molecular constitution and conformation
 Is used to solve geometric problems within a molecule
 Relative stereochemistry can be seen
 Regiochemistry can be seen
 Powerful technique for 3D study of proteins and other macromolecules
Aiding assignments
Investigating molecular motions
 Nuclear Overhauser Enhancement
Applications
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+45%
+18%
- 2%
+17%
- 4%
semiclathrate
Dimethylformamide
3-methylcrotonic 
acid
 Nuclear Overhauser Enhancement
two Me groups are non-
equivalent owing to hindered 
rotation about the C-N bond.
Both Me signals are therefore found
At  2.79 and  2.94, together with a singlet
at  8.0 for the formyl proton. If one now saturates the Me signal at  2.94, the intensity of the formyl proton signal increases by 18%. When instead the other methyl signal is saturated, a decrease of 2% is observed.
Which methyl signal belongs
to which group?
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NOESY
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HMBC
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HMBC of Codeine
H-8 to aromatic carbons C-1 
and C-6 ( both are three bond
 coupling
C-6
C-1
C-2
H-8
H-9 to aromatic carbons C-1,
C-3 and C-4 ( both are three
 bond coupling
H-9
C-3
C-4
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Pulsos em RMN 2D
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