N
X
C
Hal
O
N
S
P Si
Natural
Products
Solvents
C
C
C
C C
C
237
5.12 Miscellaneous Compounds
237
5.12 Miscellaneous Compounds
5.12.1 Compounds with Group IV Elements
Silicon Compounds (δ in ppm, J in Hz)
Coupling with silicon: The isotope 29 Si (natural abundance, 4.7%) has a spin quantum number I of 1/2. Doublets with the corresponding intensity ("Si satellites") are
usually observed. Typical coupling constants:
H 3 C Si
CH 3
CH 3
CH 3
H 3 C Si
CH 3
CH 3
H
H 3 C Si
CH 3
H
H
H 3 C Si
H
H
H
Cl Si
Cl
CH 3
CH 3
H 3 C Si
Cl
CH 3
CH 3
H
H
H
Si
CH 3
CH 3
CH 3
O Si
O
O
H
H
Si
H Si
H
H
N Si H
H
H
CH 3
1 J HSi -150 to -380
2 J HCSi 5 to 10
H Si
H
H
H
Si
CH 3
H
CH 3
1 J HSi -202.5
1 J HSi -199.1
2 J HCSi 7.0
1 J HSi -194.6
3 J HSiCH 4.7
1 J HSi -188.5
2 J HCSi 7.7
3 J HSiCH 4.3
1 J HSi -181.7
2 J HCSi 8.8
3 J HSiCH 3.8
1 J HSi -189
2 J HCSi 7.6
3 J HSiCH 3.6
1 J HSi -209.4
3.20
0.00
4.29
5.47
3.85
1.25
7.56
7.31
7.37
6.11
0.06
5.88
5.63
0.79
7.53
7.3
7.3
0.33
2.63
4.45
4.35
3.71
4.03
4.00
0.27
0.26
0.08
0.42
1.14
Cl Si
Cl
Cl
CH 3
3 J ab 14.6
3 J ac 20.2
2 J bc 3.8
a
b
c
H 3 C Si
CH 3
CF 2
CH 3
P
OH
OH
O
pH-dependent shift of the methyl H atoms relative to DSS.
Between pH 4.3 and 8.2 [1]:
pH = 6.246 - log
0.224 - δ
δ - 0.193
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