SCH-Br
•Summary of spectra vs T, (slides: 3-7 (“hot”); 10-11(“cold”))
•calc. vs. exp. chemical shift differences for ax.-eq. (C2-C6, C3-C5, C4)
(slides 11)
•DNMR-analysis for C3-C5 (slides: 12-14)
PPT´s:
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-160712.ppt
IGOR´s:
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
XLS´s :
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls
https://notendur.hi.is/agust/rannsoknir/SCH/July12/ibrcl-silacyclo-nmr.xlsx
H
Si
Br
Br
Si
H
nuts and txtTNMR [K]
z
Tcorr [K]
file names
i:
180 -0.31566825 167.889512 SCH-Br-180-150712i b
170 -0.50446504 158.645267
b
160 -0.69326184 149.73963
b
156 -0.76878056 146.240126
b
152 -0.84429928 142.757617
b
148
-0.919818 139.276588
b
144 -0.99533672 135.77923
b
140 -1.07085544 132.245325
b
136 -1.14637416 128.652129
b
132 -1.22189288 124.974252
b
128 -1.2974116 121.183542
b
124 -1.37293032 117.24897
b
high
b
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls
size/K
64
64
64
64
64
64
64
64
64
64
64
64
64
SCH-Br
TNMR [K]
1600
Tcorr [K]
high
180 167.889512
1400
170 158.645267
1200
160 149.73963
156 146.240126
1000
152 142.757617
148 139.276588
144 135.77923
800
140 132.245325
136 128.652129
600
132 124.974252
C3,C5
C4
C2,C6
400
128 121.183542
200
124 117.24897
0
30
25
20
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
15
ppm
SCH-Br
TNMR [K]
1600
Tcorr [K]
high
180 167.889512
1400
170 158.645267
1200
160 149.73963
156 146.240126
1000
152 142.757617
148 139.276588
144 135.77923
800
140 132.245325
136 128.652129
600
132 124.974252
C2,C6
400
128 121.183542
200
124 117.24897
0
17
16
15
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
14
ppm
SCH-Br
TNMR [K]
X
1600
Tcorr [K]
high
180 167.889512
1400
170 158.645267
1200
160 149.73963
156 146.240126
1000
152 142.757617
148 139.276588
144 135.77923
800
140 132.245325
136 128.652129
600
132 124.974252
C3,C5
400
128 121.183542
200
eq.
ax.
X
124 117.24897
0
27
26
25
24
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
23
22
ppm
SCH-Br
TNMR [K]
Tcorr [K]
1600
high
180 167.889512
1400
170 158.645267
1200
160 149.73963
156 146.240126
1000
152 142.757617
148 139.276588
144 135.77923
800
140 132.245325
136 128.652129
600
132 124.974252
C4
400
128 121.183542
200
124 117.24897
0
32
31
30
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
29
ppm
SCH-Br
600
132 124.974252
500
400
300
128 121.183542
Calc,
200
ax.-eq = +0.34
-3.83
-2.14
100
C4
C3,C5
C2,C6
124 117.24897
0
30
25
20
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
15
ppm
https://notendur.hi.is/agust/rannsoknir/SCH/July12/ibrcl-silacyclo-nmr.xlsx
Comments:
• Chemical shift calculations seem to overestimate
abs(ax.-eq.) spacings for C2/C6 & C3/C5
•Not clear what is the case for C4
•Only possible to determne chemical shift for eq. For
C3,C5
•Further cooling needed to determine chemical shifts for
eq. For C2,C6 and C4
New “colder” spectra added:
SCH-Br
TNMR [K] Tcorr [K]
TNMR [K]
Tcorr [K]
high
1500
180 167.889512
170 158.645267
160 149.73963
160 149.7396
156 146.240126
152 142.757617
1000
150
141.018
148 139.276588
144 135.77923
140 132.245325
140 132.2453
136 128.652129
132 124.974252
500
130 123.0949
128 121.183542
C3,C5
C4
C2,C6
124 117.24897
0
124
117.249
120 113.1365
117 109.9132
30
25
20
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
15
ppm
SCH-Br
TNMR [K] Tcorr [K]
600
132 124.974252
400
130 123.0949
128 121.183542
200
C3,C5
C4
C2,C6
124 117.24897
0
124
117.249
-200
120 113.1365
eq
-400
eq
117 109.9132
30
25
20
15
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp , Layout:0, Gr:0
ppm
TNMR [K] Tcorr [K]
SCH-Br
0
-100
124
117.249
-200
C3,C5
C4
C2,C6
120 113.1365
-300
25.78859 ppm
22.89449 ppm
ax.-eq =
+0.34
-400
-3.83
-2.889
-2.14
eq
eq
-1.284
Calc.
Exp.
117 109.9132
30
25
20
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-Sp.%20vs%20T-150712.pxp
15
ppm
https://notendur.hi.is/agust/rannsoknir/SCH/July12/ibrcl-silacyclo-nmr.xlsx
parameter
value
R
<T>
K(eq->ax)
unit
8.315 J K-1 mol-1
128.5 K
5.993006993 -
%a(e) (low field; Cl
eq)
14.3
%b(a) (high field:
Cl3 ax)
85.7
DG(eq->ax)
-1913.20864 J mol-1
DG(eq->ax)
-1.91320864 kJ mol-1
DG(eq->ax)
-0.45725687 kcal mol-1
conversion factor
kB
h
R
0.239 kcal/kJ
1.381E-23 J K-1
6.626E-34 J s
8.315 J K-1 mol-1
DG#
(eq->#; see below)
eq
G
ax
Si
Br
Si
Br
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls
C3,C5 analysis:
kcal mol-1
DG#(eq->#)
5.152817
5.250984
5.354135
5.462203
5.772349
5.465736
5.426652
Tc
109.9131943
113.1365063
117.2489699
123.0948716
132.2453248
141.0179753
149.7396298
ksum
152
198
299
601
930
11613
43793
k(eq->ax) k(ax->eq)
130.264
21.736
169.686
28.314
256.243
42.757
515.057
85.943
797.01
132.99
9952.341
1660.659
37530.6
6262.399
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-X-Sp.%20vs%20T-150712.xls
6.0
5.8
DG#
(eq->#)
Coefficient values ± one standard deviation
a
=4.4628 ± 0.618
b
=0.0074972 ± 0.00485
5.6
5.4
Average:
5.2
5.412125
+/- 0.13669699
5.0
DG# = DH# -TDS# =>
DH# = 4.46 kcal mol-1;
DS# = +0.0075 kcal mol-1K-1 / +7.5 cal mol-1K-1
4.8
4.6
110
115
120
125
130
135
140
145
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-T-080812.pxp Lay:,0 Gr:0
Tcorr
C3,C5 analysis:
Or parabola fit:
Coefficient values ± one standard deviation
K0
=-9.9887 ± 4.34
K1
=0.23347 ± 0.0677
K2
=-0.00087287 ± 0.000261
DG#
(eq->#)
6.0
5.8
5.6
5.4
5.2
Average:
5.0
5.412125
+/- 0.13669699
4.8
4.6
110
115
120
125
130
135
140
145
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-T-080812.pxp Lay:,0 Gr:0
Tcorr
40
Simulation:
Red: exp./black dots: calc.
TNMR [K] Tcorr [K]
C3,C5
k(eq->ax):
44000
10000
30
150
141.018
140 132.2453
x10
3
800
160 149.7396
20
520
130 123.0949
260
124
170
120 113.1365
117.249
10
ax
eq
130
0
9000
8900
8800
8700
8600
8500
8400
8300
https://notendur.hi.is/agust/rannsoknir/SCH/July12/SCH-Br-T-080812.pxp Lay:,1 Gr:1
117 109.9132
Exp.
Calc.
keq,ax(s-1 )
T(K)
150
38000
141
10000
123
520
117
260
113
170
110
130
26
24
22
20
18
16