O O O O O O H H Proton Site with σ intra Organic Molecular single crystal : a specimen of arbitrary...
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Transcript of O O O O O O H H Proton Site with σ intra Organic Molecular single crystal : a specimen of arbitrary...
O
O
OO
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O H
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Proton Site with σintra
Organic Molecular single crystal : a specimen of arbitrary shape
4 point star indicates the molecule at a central location. Structure of a typical molecule on the right
Induced field calculation by discrete summation σinter
i=ii /R3i [1-(3.RRi /R5
i)]Added σinter
Shifts the
line position
single sharp line
Inner Volume Element I.V.E
I.V.E. Cavity
I.V.E Sphere
σMσIVE(S)
Discrete
Continuum
The task would be to calculate the induced field inside the cavity σcavity
In-homogeneity can cause line shape alterations:
not simply shifts only
σintra / σM
σIVE =
σinter + σM
σcavity =
σBulk +σM
In d c d F i e l d a t t h e C e n t e r o f a 'T O P "
- 4 .0 0 E - 0 7
- 2 .0 0 E - 0 7
0 .0 0 E + 0 0
2 .0 0 E - 0 7
4 .0 0 E - 0 7
6 .0 0 E - 0 7
8 .0 0 E - 0 7
7 .0 6 .0 5 .0 4 .0 3 .0 2 .0 1 .0 0 .0 1 .0 - 2 .0 - 3 .0 - 4 .0 - 5 .0 - 6 .0 - 7 .0
D i s t 'Y ' f r o m C e n t e r ' 0 '
Indc
d Fi
elds
at c
ente
r
I n d c d ie ld a t th e C e n t e r x = y = 8 In d f ie ld C n t r e x = 1 6 y = 8
T h e T O P S h a p e
- 1 0
- 8
- 6
- 4
- 2
0
2
4
6
8
1 0
8 .0 6 .0 4 .0 2 .0 0 .0 - 2 .0 -4 .0 -6 .0 - 8 .0
X C o o r d in a te V a lu e
Y C
oor
din
ate
Val
ue
S e r i e s 1 S e r ie s 2
‘Y ’ V a lu e In d F ie ld
7 7 . 2 8 E - 0 7
5 4 . 6 2 E - 0 7
4 1 . 6 4 E - 0 7
2 - 2 . 6 6 E - 0 9
0 - 6 . 6 8 E - 0 8
- 2 - 2 . 6 6 E - 0 9
- 4 1 . 6 4 E - 0 7
- 5 4 . 6 2 E - 0 7
- 7 7 . 2 8 E - 0 7
The top or a Spindle Shaped object comes under the category of Shapes within which the Induced field distribution would be Inhomogeneous even if the Susceptibility is uniformly the same over the entire sample
NMR Line for only Intra molecular Shielding
Added intermolecular Contribultions causes a shift downfield or upfield
homogeneous
Inhomogeneous Magnetization can CauseLine shape alterations
4. The case of Shape dependence for homogeneously magnetized sample, and consideration of in-homogeneously magnetized material.
A cylinder shaped specimen (Blue line in the plot below)
Zero ind. Field Points Spindle or Top shapedSpecimen (Green line in the plot below)
Not to be discussed in this presentation
The points on the Blue line would be specified and at these Calculated field values an NMR line would be placed after adding the sum total of intra and intermolecular contributions to induced fields.
Indcd Field at the Center of a 'TOP"
-4.00E-07
-2.00E-07
0.00E+00
2.00E-07
4.00E-07
6.00E-07
8.00E-07
1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0 11.0 12.0 13.0 14.0 15.0Dist 'Y' from Center ' 0 '
Indc
d Fi
elds
at c
ente
r
ind Field Cylinder x=y=8 Indcd ield at the Center x=y=8
Calculations at 9 points along the axis
Distance along the axis
No intra molecular Value; inter-molecular value (in I.V.E) set=0 in subsequent plots; only cavity field is used to generate line shapes
A graphical plot for data in TABLE-I
-3.00E-07
-2.00E-07
-1.00E-07
0.00E+00
1.00E-07
2.00E-07
7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7
position along the axial line from center
indu
ced
field
val
ueCylinder Series2
specified point w ise induced filed and nmrlines
0.00E+00
5.00E-01
1.00E+00
1.50E+00
2.00E+00
2.50E+00
2.50E-07 3.25E-07 4.00E-07 4.75E-07 5.50E-07 6.25E-07 7.00E-07 7.75E-07
induced field value
inte
nsity
arb
uni
ts
nmrlines at specied points
Cylinder
By Calculation Trend line interpolation
7 -2.87E-07 -2.9E-07
6 -1.9E-07
5 -1.87E-07 -1E-074 3.25E-08 -2.8E-08
3 2.8E-08
2 6.45E-08 6.8E-08
1 9.2E-08
0 9.35E-08 1E-07
-1 9.2E-08
-2 6.45E-08 6.8E-08
-3 2.8E-08
-4 3.25E-08 -2.8E-08-5 -1.87E-07 -1E-07
-6 -1.9E-07
-7 -2.87E-07 -2.9E-07
Only inter molecular value 5.80E-07 can be set = 0
“Only” inter-molecular value 5.80E-07 was added and the line shape was plotted with those values : NEXT GRAPHICAL PLOT
A Graph
of the data in table
Lines at interpola
ted values
Overlapping last three
lines
Add to all Values down the column
NMR lines at induced field values of specified points in material
0.00E+00
5.00E-01
1.00E+00
1.50E+00
2.00E+00
2.50E+00
3.00E+00
-3.50E-07 -2.50E-07 -1.50E-07 -5.00E-08 5.00E-08 1.50E-07 2.50E-07 3.50E-07
calculated induced field values
ampl
itude
arb
uni
ts
Lineshapes
NMRlines at induced field values of specified points in material
0.00E+00
5.00E-01
1.00E+00
1.50E+00
2.00E+00
2.50E+00
3.00E+00
-3.50E-07 -2.50E-07 -1.50E-07 -5.00E-08 5.00E-08 1.50E-07 2.50E-07 3.50E-07
calculated induced field values
ampl
itude
arb
uni
ts
Lineshapes
Same graph as displayed in previous slide
Broadening of overallshape of line
0.00E+00
1.00E+00
2.00E+00
3.00E+00
4.00E+00
5.00E+00
6.00E+00
7.00E+00
-3.50E-07 -2.50E-07 -1.50E-07 -5.00E-08 5.00E-08 1.50E-07 2.50E-07 3.50E-07
calculated induced field values
Ampl
itude
arb
uni
ts
width=5.0E-09 width=1.0E-08 width=2.0E-08 width=5.0E-08
Gradual increase of component lines broadens the lines and can cause the change in the appearance of overall shape. Illustration with 4 different width values
Same width as above
Width twice that of red
Width twice that of blue
10 times that of red Width 2.5 times that of green
Sharp line homogeneous/brodened lineshape inhomogeneous
0.00E+001.00E+022.00E+023.00E+024.00E+025.00E+026.00E+027.00E+028.00E+029.00E+02
-3.50E-07 -2.50E-07 -1.50E-07 -5.00E-08 5.00E-08 1.50E-07 2.50E-07 3.50E-07
induced field
ampl
itude
arb
uni
ts
Cylindrical w eight/w idth2.0E-08 w idth=2.0E-08 & spindle w eightfactors Only Intra Molecular
widhth 2.0E-08/No Weight factors
0.00E+00
1.00E+00
2.00E+00
3.00E+00
4.00E+00
5.00E+00
-3.50E-07 -2.50E-07 -1.50E-07 -5.00E-08 5.00E-08 1.50E-07 2.50E-07 3.50E-07
Line at σIVE
Add to all Values down the column