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1
SUPPLEMENTARY MATERIAL
1
H NMR study of the hetero-association of unsaturated alcohols with pyridine
John S. Lomasa*
CONTENTS
Figure 1 Error plots for the chemical shifts of CH protons in 2-propyn-1-ol, 2a, with parameters calculated from Eqns (2)
and (3b)
Table S1. Chemical shifts of acetylene derivatives in neat pyridine, calculated by Eqn (2) or Eqns (3): Comparison with experimental
values at 298 K
Table S2. Hetero-association constants (molar scale, standard state 1 M) and chemical shifts for association of some monohydric
alkynols and alkynes with pyridine in benzene at 298 K: Eqn (2)
Table S3. Comparison of terms in Equations (4 ) and (5)
Table S4. Taft's polar substituent constants and association constants for correlations in Figure 1
Table S5. Dissociation constants of carboxylic acids in water and pyridine association constants of alcohols in benzene, both at 298 K,
for correlations in Figure 2
2
Supp. Mat. Figure S1. Error plots for the chemical shifts of CH protons in 2-propyn-1-ol, 2a, with parameters calculated from Eqns (2)
(filled circles) and (3b) (open circles)
0,02
Eqn (2)
Shift Error/ppm
0,01
Eqn (3b)
0,00
-0,01
-0,02
0,0
0,5
1,0
1,5
2,0
Pyridine concentration/M
2,5
3,0
3
Supp. Mat. Table S1. Chemical shifts of acetylene derivatives in neat pyridine, calculated by Eqn (2) or Eqns (3): Comparison with
experimental values at 298 K
Cpd.
Group
Eqn (2)
Eqns (3)
/ppm
/ppm
Exptl.
/ppm
2a: 2-Propyn-1-ol
OH
7.010
7.277
7.188
2a: 2-Propyn-1-ol
CH
2.816
3.385
3.272
2b: 3-Butyn-2-ol
OH
7.142
7.318
7.275
2b: 3-Butyn-2-ol
CH
2.909
3.162
3.273
2c: 2-Methyl-3-butyn-2-ol
OH
7.136
7.256
7.228
2c: 2-Methyl-3-butyn-2-ol
CH
2.974
3.127
3.249
4d: 3-Butyn-1-ol
OH
6.478
6.621
6.579
4d: 3-Butyn-1-ol
CH
2.572
2.618
2.786
4e: 4-Pentyn-1-ol
OH
5.986
6.122
6.089
4e: 4-Pentyn-1-ol
CH
2.584
2.522
2.711
4f: 5-Hexyn-1-ol
OH
5.832
5.976
5.922
4f: 5-Hexyn-1-ol
CH
2.666
2.565
2.715
5g: Phenylacetylene
CH
4.135
-
4.093
5h: 1-Hexyne
CH
2.736
-
2.699
5i: 1-Octyne
CH
2.755
-
2.723
4
Supp. Mat. Table S2. Hetero-association constants (molar scale, standard state 1 M) and chemical shifts for association of some
monohydric alkynols and alkynes with pyridine in benzene at 298 K: Eqn (2)
Cpd.
K3
M/ppm
mono /ppm
Mpy/ppm
2a: 2-Propyn-1-ol (OH)
3.94±0.03
0.598±0.013
0.600
7.14±0.01
2a: 2-Propyn-1-ol (CH2)
3.92±0.06
3.701±0.003
3.699
4.43±0.01
2a: 2-Propyn-1-ol (≡CH)
0.26±0.04
2.001±0.005
1.978
3.07±0.10
2b: 3-Butyn-2-ol (OH)
2.92±0.02
1.019±0.012
1.018
7.31±0.01
2b: 3-Butyn-2-ol (CH3)
3.38±0.05
1.151±0.001
1.155
1.592±0.001
2b: 3-Butyn-2-ol (CH)
3.00±0.03
4.088±0.002
4.090
4.77±0.01
2b: 3-Butyn-2-ol (≡CH)
0.21±0.03
2.020±0.005
1.998
3.25±0.12
2c: 2-Methyl-3-butyn-2-ol (OH)
2.32±0.01
1.303±0.008
1.277
7.33±0.01
2c: 2-Methyl-3-butyn-2-ol (CH3)
2.76±0.06
1.293±0.002
1.296
2.76±0.06
2c: 2-Methyl-3-butyn-2-ol (≡CH)
0.17±0.02
2.027±0.005
2.007
3.42±0.11
4d: 3-Butyn-1-ol (OH)
1.59±0.01
0.947±0.008
0.926
6.75±0.01
4d: 3-Butyn-1-ol (HOCH2)
1.78±0.01
3.261±0.001
3.263
3.98±0.01
4d: 3-Butyn-1-ol (≡CHCH2)
1.62±0.02
1.986±0.001
1.984
2.56±0.01
4d: 3-Butyn-1-ol (≡CH)
0.14±0.02
1.685±0.004
1.669
3.08±0.10
4e: 4-Pentyn-1-ol (OH)
1.55±0.01
0.474±0.003
0.456
6.27±0.01
4e: 4-Pentyn-1-ol (HOCH2)
1.56±0.12
3.309±0.009
3.290
3.925±0.011
4e: 4-Pentyn-1-ol (HOCH2CH2)
1.63±0.02
1.400±0.001
1.400
1.892±0.001
4e: 4-Pentyn-1-ol (≡CHCH2)
1.39±0.05
2.005±0.002
2.001
2.425±0.003
4e: 4-Pentyn-1-ol (≡CH)
0.082±0.008
1.722±0.002
1.715
3.424±0.121
5g: Phenylacetylene (≡CH)
0.059±0.002
2.712±0.001
-
6.06±0.08
5h: 1-Hexyne (≡CH)
0.035±0.002
1.767±0.001
-
4.93±0.19
5i: 1-Octyne (≡CH)
0.037±0.001
1.783±0.001
-
4.88±0.06
5
Supp. Mat. Table S3. Comparison of terms in Equations (4 ) and (5)
(M)' + (M)"
(AA)' + (AA)"
mono
K3' + K3"
K7 + K8
K3'K3"
K7K9
2a
2.60
2.55
2.58
4.20
4.14
1.02
0.13
2b
3.04
2.99
3.02
3.13
3.14
0.61
0.20
2c
3.33
3.29
3.28
2.49
2.47
0.39
0.18
4d
2.63
2.60
2.60
1.73
1.82
0.22
0.17
4e
2.20
2.17
2.17
1.63
1.81
0.13
0.19
4f
2.14
2.12
2.12
1.38
1.55
0.07
0.14
Cpd.
Cpd.
K3'K3"Mpy
K7K9AApy2
K3"[(M)' + (Mpy)"]+
K3'[(M)" + (Mpy)']
K8[(AA1)' + (AApy)"]+
K7[(AA1)" + (AApy)']
2a
10.5
1.9
37.0
37.9
2b
6.5
2.5
28.1
28.9
2c
4.2
2.1
22.5
22.8
4d
2.2
1.8
14.0
14.6
4e
1.2
1.9
12.7
13.5
4f
0.7
1.4
10.7
11.4
6
Supp. Mat. Table S4. Taft's polar substituent constants and association constants for correlations in Figure 1
Compound
σ*
Ref.
log K3
Ref.
Methanol
0.00
(a)
0.188
(g)
Ethanol
-0.10
(a)
0.086
(g)
Propan-1-ol
-0.115
(a)
0.117
(h)
Propan-2-ol
-0.19
(a)
0.009
(g)
Butan-1-ol
-0.13
(a)
0.107
(h)
Butan-2-ol
-0.21
(a)
-0.051
(j)
2-Methylpropan-1-ol
-0.125
(a)
0.127
(g)
2-Methylpropan-2-ol
-0.30
(a)
-0.104
(g)
2,2-Dimethylpropan-1-ol
-0.165
(a)
0.155
(g)
Pentan-3-ol
-0.225
(a)
-0.199
(g)
3,3-Dimethylbutan-2-ol
-0.28
(a)
-0.056
(j)
(tert-Butyl)2CHOH
-0.332
(b)
-0.058
(b)
(tert-Butyl)2MeCOH
-0.431
(b)
-0.264
(b)
(tert-Butyl)2EtCOH
-0.444
(b)
-0.492
(b)
(tert-Butyl)2iPrCOH
-0.457
(b)
-0.506
(b)
(tert-Butyl)3COH
-0.498
(b)
-0.398
(b)
(tert-Butyl)2NeopCOH
-0.450
(b)
-0.547
(b)
Benzyl alcohol
0.215
(a)
0.387
(g)
2-Propyn-1-ol
0.5
(c)
0.601
(i)
3-Butyn-1-ol
0.15
(d)
0.200
(i)
4-Pentyn-1-ol
0.01
(d)
0.190
(i)
-0.07
(d)
0.124
(i)
2-Propen-1-ol
0.13
(e)
0.255
(i)
3-Buten-1-ol
0.04
(d)
0.083
(i)
5-Hexyn-1-ol
7
4-Penten-1-ol
-0.08
(d)
0.114
(i)
2,2,2-Trifluoroethan-1-ol
0.92
(a)
1.161
(i)
2-Cyanoethan-1-ol
0.48
(f)
0.731
(i)
2-Chloroethan-1-ol
0.385
(a)
0.38
(i)
(a) R. W. Taft, in Steric Effects in Organic Chemistry, (Ed. M. S. Newman), John Wiley and Sons Inc., New York, 1956, Chapter 13, pp. 556-675.
(b) J. S. Lomas, J. Phys. Org. Chem. 2005, 18, 1001-1012.
(c) PhC≡C is given as 1.35. Reducing this by a damping factor of 2.7 gives 0.50 for PhC≡CCH2, which we take as a fair approximation to HC≡CCH2.
(d) See below.
(e) CH3CH=CHCH2 is given as 0.13; we take this as a fair approximation to H2C=CHCH2.
(f) NCCH2 is given as 1.35, to which we apply a damping factor of 2.7.
(g) J. S. Lomas, F. Maurel, J. Phys. Org. Chem. 2008, 21, 464-471.
(h) J. S. Lomas, J. Phys. Org. Chem. 2011, 24, 129-139.
(i) This work.
(j) J. S. Lomas, F. Maurel, A. Adenier, J. Phys. Org. Chem. DOI 10.1002/poc.1831
Note. It is not easy to estimate Taft's constants for substituents with methylene chains longer than those given in his work. For several electronattracting groups, going from RCH2 to R(CH2)2 divides the Taft constant by a factor of about 2.7, whereas going from H-CH2 to H-(CH2)2 reduces the
constant from 0.00 to –0.10, further methylenes reducing the value to –0.115 (n-propyl) and –0.13 (n-butyl); there are no more data. This means that in
the case of electron-attractors we cannot blindly apply a factor of 2.7 to the addition of a methylene group, as this would result in zero values for any R
connected by a long chain to the functional group. A long chain with an electron-attractor (or electron-donor) at the end is expected to resemble a long
chain with a hydrogen at the end, which implies a value of –0.13 or slightly lower. We have tried to take account of these contrary effects by
introducing an increment for chain lengthening (–0.1, –0.115, –0.13) and a factor of 0.5 for each methylene group. This procedure works relatively
well for the CF3(CH2)n series (n = 1, 2, 3) but we do not claim that is gives more than a rough idea of the polar constants for the unsaturated
substituents.
8
Supp. Mat. Table S5. Dissociation constants of carboxylic acids in water and pyridine association constants of alcohols in benzene, both
at 298 K, for correlations in Figure 2
Acid
pKa
Alcohol
CH3CO2H
4.757
Methanol
0.185
CH3CH2CO2H
4.876
Ethanol
0.086
CH3(CH2)2CO2H
4.821
Propan-1-ol
0.117
(CH3)2CHCO2H
4.860
Propan-2-ol
0.009
CH3(CH2)3CO2H
4.842
Butan-1-ol
0.107
(CH3CH2)CH3CHCO2H
4.807
Butan-2-ol
-0.051
(CH3)3CCO2H
5.033
2-Methylpropan-2-ol
-0.102
CH3CH2(CH3)2CCO2H
5.032
2-Methylbutan-2-ol
-0.155
C6H11CO2H
4.900
Cyclohexanol
-0.041
PhCH2CO2H
4.312
Benzyl alcohol
0.391
HC≡CCH2CO2H
3.32
2-Propyn-1-ol
0.602
HC≡C(CH2)2CO2H
4.21
3-Butyn-1-ol
0.201
HC≡C(CH2)3CO2H
4.60
4-Pentyn-1-ol
0.190
HC≡C(CH2)4CO2H
4.61
5-Hexyn-1-ol
0.124
H2C=CHCH2CO2H
4.349
2-Propen-1-ol
0.251
H2C=CH(CH2)2CO2H
4.676
3-Buten-1-ol
0.083
H2C=CH(CH2)3CO2H
4.72
4-Penten-1-ol
0.114
Trifluoroethanol
1.155
F3CCH2CO2H
3
log K3
NC(CH2)2CO2H
4.00
Cyanoethanol
0.380
Cl(CH2)2CO2H
4.00
Chloroethanol
0.736
9
Dissociation constants of acids taken from: (a) G. Körtum, W. Vogel, K. Adrussow, Dissociation Constants of Organic Acids in Aqueous Solution,
Butterworths, London, 1961. (b) G.H. Mansfield, M. C. Whiting, J. Chem. Soc. 1956, 4761-4764.