hcooh nmr presentation
TRANSCRIPT
NMR titrationHCOOH; CH3COOH; NaNO2
HCOOH1) 1.0 μL H2SO4 50 μL H2
18O
18
18
18
18
2) 40.5 μL DMF570 μL D2O
18
18
18
18
40 μL 1.5M
3) 6 μL 50% NaOH per aliquot during titration
unlabeled Monolabeled dilabeled
HCOOH (fully protonated) and DMF
NB1p20formic1_C_part-1.jdf
165.9 165.8 165.7 165.6 165.5 165.4 165.3 165.2 165.1 165.0 164.9 164.8 164.7 164.6Chemical Shift (ppm)
unlabeled
dilabeled
monolabeled
B1P2O-a #284-310 RT: 1.43-1.56 AV: 27 SB: 13 1.18-1.24 NL: 3.21E6T: - c Full ms [ 30.00-80.00]
38 40 42 44 46 48 50 52 54 56 58m/z
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Rel
ativ
e A
bund
ance
47.12
45.11
49.12
46.28 48.2044.34 58.3657.1950.1042.02 43.2240.17
Formic Acid.esp
6.0 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 -0.5Chemical Shift (ppm)
Standardization: credit to Katie
All acid (0% reacted)
Predicted 50%-reacted point
All formate (100% reacted with NaOH)
DMF
Many thanks to Katie for standardization(δun
0-δun)(δmono-δmono-)= (δun-δun-)(δmono0-δmono)
calibration
0 1 2 3 4 5 6 7 80
1
2
3
4
5
6
7
8
f(x) = 1.0134289299868 x − 0.000509406394531009R² = 0.999999912992084
un/mono16O16O/16O18O
(δun-δun-)(δmono0-δmono)
(δun
0-δu
n)(δ
mon
o-δm
ono-
)
• δ0:shift of acid prior to adding base
• δ-:shift of anion when acid-base rxn is complete
• Other variables dependent on extent of ionization
Mono/di unnecessary? For mono/di: (δmono
0-δmono)(δdi-δdi-)= (δmono-δmono-)(δdi0-δdi)
un/mono VS mono/di
0 1 2 3 4 5 6 7 80
1
2
3
4
5
6
7
8
f(x) = 1.0134289299868 x − 0.000509406394531009R² = 0.999999912992084
un/mono16O16O/16O18O
(δun-δun-)(δmono0-δmono)
(δun
0-δu
n)(δ
mon
o-δm
ono-
)
0 1 2 3 4 5 6 7 80
1
2
3
4
5
6
7
8
f(x) = 1.0136595412 x − 0.0014119207R² = 0.999999811668334
mono/di16O18O/18O18O
(δm
ono0
-δm
ono)
(δdi
-δdi
-)
(δmono-δmono-)(δdi0-δdi)
(δun0-δun)(δdi-δdi-) =(δun-δun-)(δdi
0-δdi)
16O16O/18O18O (un/di)
0 1 2 3 4 5 6 7 80
1
2
3
4
5
6
7
8
f(x) = 1.0272702612 x − 0.0019261323R² = 0.999999743202866
un/di16O16O/18O18O
(δun-δun-)(δdi0-δdi)
(δun
0-δu
n)(δ
di-δ
di-)
Ka ratio:Un/mono/di = 1.0273/1.0137/1
18
18 18
18
Acetic acid (fully protonated)
Inez_NB1p11_Sample2_13C-4.jdf
176.55 176.50 176.45 176.40 176.35 176.30 176.25 176.20 176.15 176.10Chemical Shift (ppm)
Significant increase in height after more unlabeled acetic acid is added
18
18
CH3COOH and DMF credit to KatieAcetic Acid.esp
16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0Chemical Shift (ppm)
Calibration
Many thanks to Katie for standardization
0 1 2 3 4 5 60
1
2
3
4
5
6
7
f(x) = 1.01250562256214 x + 0.000137612538945398R² = 0.999999683533146
UN/MONO
0 1 2 3 4 5 601234567
f(x) = 1.01167825599676 x + 0.00568749995565909R² = 0.999993388828339
MONO/DI
0 1 2 3 4 5 601234567
f(x) = 1.02441687216787 x + 0.00538982102030294R² = 0.999993059171215
UN/DI
Kaun:Kamono:Kadi:
CH3COOH: 1.0244:1.0117:1
HCOOH: 1.0273:1.0137:1
Blp22-a #356-383 RT: 2.01-2.16 AV: 28 SB: 41 1.48-1.71 NL: 3.75E5T: - c Full ms [ 30.00-80.00]
30 35 40 45 50 55 60 65 70 75 80m/z
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
Rel
ativ
e A
bund
ance
62.18
46.16
47.2036.68
Attempted HNO2 synthesis
[M1-H]-
[M2-H]-
BlP22ESI Negative Ion Mode
HNO2
HNO3
Na15NO2 SPECTRA
181818
18
1818