278
278
19 F Chemical Shifts of CF 3 Groups (δ in ppm)
Substituent
δ
–H
-78
–CH 3
-62
–CH 2 CH 3
-70
–n-C 7 H 15
-67
–CH 2 OH
-78
–CH 2 NH 2
-72
–CH 2 COOH
-64
–CH 2 CH 2 –1-pyridinium -75
–C(CF 3 ) 3
-65
–CF 3
-89
–CF 2 CF 3
-83
–perfluorocyclohexyl
-70
–CCl 3
-82
–CH=CH 2
-67
–C– – – CH
-56
–phenyl
-64
–C 6 F 5
-55
–4-nitrophenyl
-64
–4-aminophenyl
-62
–C 6 (CF 3 ) 5
-53
–1-naphthyl
-75
–2-naphthyl
-73
–2-pyridyl
-68
–3-pyridyl
-62
–4-pyridyl
-65
Substituent
δ
–F
-63
–Cl
-29
–Br
-18
–I
-5
–OH
-55
–O–cyclohexyl
-58
–O–CF 3
-58
–O–phenyl
-58
–O–CO–CO–O–CF 3
-31
–NH 2
-49
–C– – – N
-53
–NC
-51
–SH
-32
–S–CF 3
-39
–SS–CF 3
-47
–SO 3 H
-79
–S(O) 2 –phenyl
-79
–COCF 3
-85
–CO–phenyl
-58
–COOH
-77
–COO –
-74
–COOCH 2 CH 3
-74
–COF
-76
–P(O)(OCH 2 CH 3 ) 2
-73
–P(CF 3 ) 2
-51
–P + (phenyl) 3
-58
C
X
O
N
S
O
 ||
C
P
Heteronuclear NMR Spectroscopy
6