Understanding NMR Spectroscopy phần 3 potx
Understanding NMR Spectroscopy phần 3 potx
... protons. Does this have a significant effect of the carbon- 13
nuclei? Explain your answer carefully.
E 3 6
Referring to the plots of Fig. 3. 26 we see that there are some offsets at which
the transverse ... the tail of the FID, but still less
than the matched filter.
3. 12 Exercises 3 21
come about when the magnetization executes complete 36 0
◦
rotations about
the effective field. In suc...
Understanding NMR Spectroscopy phần 2 potx
... a pulse NMR experiment. The whole process is
analogous to the way in which electric current can be generated by a magnet
rotating inside a coil.
3. 4 Pulses 3 3
z
x
M
0
sin β
β
Fig. 3. 4 Tilting ... sin 2θ.
following frequencies, in Hz, (intensities are given in brackets): 32 .0 (1 .3) ,
39 .0 (0.7), 6.0 (0.7), 13. 0 (1 .3) . Determine the values of the coupling constant
and the two...
Muhammad ayub understanding islamic finance phần 3 potx
... the Islamic law of contracts in
modern-day operations.
32
Ibnul Qayyim, 1955, 3.
33
Zuhayli, 20 03, 1,p.74.
34
For details see Zuhayli, 20 03, pp. 71, 72.
Islamic Law of Contracts and Business Transactions ... the agreement.
38
There are three types of conditions according to Hanafis: valid, defective and invalid; see Zuhayli, 20 03, 1, pp. 1 23 131 .
39
Mansoori, 2005, pp. 157–1 6...
Understanding NMR Spectroscopy phần 1 ppt
... α
1
2
+
1
2
ν
0,1
−
1
2
ν
0,2
+
1
2
ν
0 ,3
−
1
4
J
12
+
1
4
J
13
−
1
4
J
23
3 βαα
1
2
−
1
2
ν
0,1
+
1
2
ν
0,2
+
1
2
ν
0 ,3
−
1
4
J
12
−
1
4
J
13
+
1
4
J
23
4 ββα −
1
2
−
1
2
ν
0,1
−
1
2
ν
0,2
+
1
2
ν
0 ,3
+
1
4
J
12
−
1
4
J
13
−
1
4
J
23
5 ααβ
1
2
+
1
2
ν
0,1
+
1
2
ν
0,2
−
1
2
ν
0 ,3
+
1
4
J
12
−
1
4
J
13
−
1
4
J
23
6 ... 4–8).
Subspectra
ααα
αβα
ββα
βαα
1
23
4
ααβ
αββ
β...
Understanding NMR Spectroscopy phần 4 doc
... probe 5 3
5.2 The probe
The probe is a cylindrical metal tube which is inserted into the bore of the
magnet. The small coil used to both excite and detect the NMR signal (see
sections 3. 2 and 3. 4) ... introduced in Chapter 3, is very useful for describing basic
NMR experiments but unfortunately is not applicable to coupled spin systems.
When it comes to two-dimensional NMR many of...
Understanding NMR Spectroscopy phần 6 pps
... simply
(J
12
+J
23
). Taking each term in turn
Bt
BtJJt
BtJJtI
B
y
JtII JtI I
y
zx
zz zz
13 3 1
22
13 3 1 12 23 1
13 3 1 12 23 1 2
13
12 1 1 2 23 1 2 3
2
cos DQ
cos cos DQ
cos sin DQ
1
13
1
13
1
13
ΩΩ
ΩΩ
ΩΩ
+
()
→
+
()
+
()
−+
()
+
()
−
()
+
()
()
ππ
π
π
sin
ΩΩΩ
ΩΩ
ΩΩ
1
13
1
13
1
13
DQ
cos ... to
B
BtBt
y
tI tI tI
yx
zzz
13
13 3 1 13 3 1
11 1 21 2 31 3...
Understanding NMR Spectroscopy phần 7 ppsx
... uses coherence transfer pathways to specify the
desired outcome of the experiment.
9.2 Phase in NMR
In NMR we have control over both the phase of the pulses and the receiver
phase. The effect of ... as
Gt FtFt FtFt FtFt
FtF t
,
***
*
ττττ
τ
()
=
()
+
()
+
()
+
()
+
()
+
()
+
=
()
+
()
11 2 2 33
K
F
1
(t) is the field experienced by spin 1 at time t, and F
1
(t+
τ
) is the field
experi...
Understanding NMR Spectroscopy phần 8 ppsx
... reduced to be in the range 0 to
36 0° by subtracting multiples of 36 0° (e.g. for step 3 we subtracted 36 0° and
for step 4 we subtracted 720°).
If we wished to select ∆p = 3 we would simply shift the ... 0
10 90 –90 180 36 0 270 270
11 180 –180 180 36 0 180 180
12 270 –270 180 36 0 90 90
13 0 0 270 540 540 180
14 90 –90 270 540 450 90
15 180 –180 270 540 36 0 0
16 270 –270 270 54...
Understanding NMR Spectroscopy phần 9 pps
... 0 1 2 3 2 3
0 1, 2nd pulse: 0 1 2 3 0 1 2 3, 3rd pulse fixed, receiver: 0 0 0 0 2 2
2 2.
An alternative is to cycle the last pulse to select the pathway ∆p = –1, giving
the cycle 0 1 2 3 for ... beginning
9 30
10000
2 90 90 180 0
3 180 180 0 0
4 270 270 180 0
We can play one more trick with this phase cycle. As the third pulse is required
to achieve the transformation
∆p
= 3 or...
Understanding NMR Spectroscopy phần 10 pdf
... frequencies in F
2
/ Hz
a 30 Transferred to 30
b 30 and 60 transferred to 30
c 60 transferred to 30 and 60
d 30 transferred to 20, 30 and 60
e 30 and 60 transferred to 30 and 60
E7 -3. What would the ... →
→
→
→
()
++
()
()
++
()
π
π
π
22
4
12
2
12 3
2
1
2
2
23 2 3
23 2 3
12 1 2
13 1 3
II
II I
I
zx
JtI I
zyz
JtI I
x
JtII
tJ I I
zz
zz
zz
zz
π
π
π
π
→...