285
6.2.6 19 F Chemical Shifts and Coupling Constants of Aromatics and
Heteroaromatics (δ in ppm relative to CFCl 3 , J FF in Hz)
Estimation of 19 F Chemical Shifts of Substituted Fluorobenzenes [4]
Substituent
Z 2,6
Z 3,5
Z 4
–CH 3
-3.9
-0.4
-3.6
–CF 3
0.4
3.1
5.8
–CH=CH 2
-4.4
0.7
-0.6
–C– – – CH
–
–
3.3
–F
-23.2
2.0
-6.6
–Cl
-0.3
3.5
-0.7
–Br
7.6
3.5
0.1
–I
19.9
3.6
1.4
–OH
-23.5
0.0
-13.3
–OCH 3
-18.9
-0.8
-9.0
–OCOCH 3
–
–
-3.7
–NH 2
-22.9
-1.3
-17.4
–NHCOOCH 3
–
0.1
-7.1
–NHCONH 2
–
0.9
-8.1
–N 3
-11.4
2.8
-0.3
–NO 2
-5.6
3.8
9.6
– C– – – N
6.9
4.1
10.1
–NCO
-9.2
2.3
-2.2
–SH
10.0
0.9
-3.5
–SCH 3
6.5
1.2
-4.5
–S(O) 2 F
7.5
5.8
13.8
–S(O) 2 –CF 3
9.5
5.5
-14.3
–S(O) 2 OCH 2 CH 3
–
3.7
9.1
–CHO
-7.4
2.1
10.3
–COCH 3
2.5
1.8
7.6
–COOH
2.3
1.1
6.5
-COOCH 3
3.3
3.8
7.1
–CONH 2
0.5
-0.8
3.4
–COF
-14.8
3.0
6.2
–COCl
3.4
3.5
12.9
–B(OH) 2
6.8
0.8
2.1
–Si(CH 3 ) 3
13.8
0.3
1.6
C
X
O
N
S
O
||
C
M
2
3
4
δ F = -113.9 + ∑ Z i
6
5
F
6.2 19 F NMR Spectroscopy