C8953
NMR structural analysis - seminar
1D 13C-NMR + APT
Ondrej Jurcek, Martin Novak
jurcekondre j @mail.muni. cz, 32 34 60@mail.muni.cz
February 28, 2018
vs 13C NMR
	1H	13C
Spin number	1H:s=| x 2H:s=1	13C:s=l x 12C:s=0
Abundance [%]	99.98	1.1
Gyromagnetic ratio [107 rad.T~1.s~1]	26.8	6.7
Chemical shift range [ppm]	0-15	0-200
Nuclear shielding		<3"dia + fpara
Integration of signals	/	X
7i relaxation [s]	1-20	1-40
Homonuclear J-interaction	/	X
H^C J-interaction (~ 100-250 Hz)	carbon satellites	(n+ 1) splitting x decoupling
1D 1H NMR
U)c+0.51JHc
U)r-0.51J,
HC
H-13Ca
1H-13C(3
1D 13C NMR
kJkJ
Ha-13C
1Hp-13C
12,
1H decoupled
— -o<\<y
vs 13C NMR
H 13C
Spin number	1H:s=| x 2H:s=1	13C:s=l x 12C:s=0
Abundance [%]	99.98	1.1
Gyromagnetic ratio [107 rad.T~1.s~1]	26.8	6.7
Chemical shift range [ppm]	0-15	0-200
Nuclear shielding		<3"dia + fpara
Integration of signals		X
7i relaxation [s]	1-20	1-40
Homonuclear J-interaction		X
H^C J-interaction (~ 100-250 Hz)	carbon satellites	(n+ 1) splitting x decoupling
Important regions of 13C chemical shifts
i
Aldehydes RCH=
0
R2C—CH2
Ketones R1R2C=0 I-1
RHC=CHR h
J_
i—
C-l
Alkenes R2C=CH2|-1
Aromatics
Heteroaromatics
Carboxylic acids R-C02H I-1
Esters R-C02R' I-1
C-Br
H
C-NO,
C-H Saturated Hydrocarbons
C-NH;
H
H h
C-OH
C-SR
I RC=N ! C-OR |
^Ar^
C-S02R r-C=C I--H UU U I
Amines R-CONR2 I-1
Alkynes C=CR I- h
H C-CO R
200
150
100
ppm(5)
50
0.0
1 Jch depends on the bond order ( hybridization <^> s-character)
► -C-H 1JCH ~ 125 Hz
► =C-H 1JCH ~ 160 Hz
► =C-H 1JCH ~ 250 Hz
► X-C-H
► X = N,0, S, F,CI,     Jch ft
► X = Li, Mg,     JCH ft
2 Jch < 0 or close to zero (<3 Hz)
► often not observable
Values of chemical shift of important solvents
Abbr.	Formula	1H	13C
ACN	CH3CN	1.9	118
Benzene	CeHe	7.2	128
	CHCI3	7.2	77
DCM	CH2CI2	5.3	54
DMF	(CH3)2NCHO	2.9, 8.0	32, 163
DMSO	(CH3)2SO	2.5	40
MeOH	CH3OH	3.3, 4.8	49
Water	H20	4.8	-
Effect of solvent on the position of residual1H water signal CHCI3 -1.6, ACN - 2.1, DMSO - 3.3, MeOH - 4.9
How many 13C signal would you expect in the NMR spectrum?
H
N
CI
N
Ru
N
CI
CI
S
CH3
3C-NMR 1
C-NMR 2
1D13C-NMR3
APT - Attached Proton Test
based on heteronuclear spin echo
► ti =V1JCH
13C signals are differentiated according to the number of directly bound 1H
► Cq, CH2 positive
► CH, CH3 negative
Evolution of signal governed by the value of 1JCh =^ reflected by the intensity of APT signal
ti
-
90x 180y
C-13-^---
: 80
0 0.5 1 1.5 2
dec . a . .
H-l -1-1-1 I1 H' JCh)
13C APT Cinnamic acid
13C APT CINNAMIC ACID
TT
OH
165
160
155
150
145
140
135
130
125
120
■ i ' 1 ' ' i 115 ppm
13C APT of Nicotine
DMSO
-4-
150      140     130      120      110      100      90       80       70       60       50       40       30 ppm