electronic supporting information for on a nucleophilic ... · rebecca r. hawker, ronald s. haines...

Electronic supporting information for

“The effect of varying an ionic liquid anion on the solvent effects

on a nucleophilic aromatic substitution reaction”

Rebecca R. Hawker, Ronald S. Haines and Jason B. Harper*

School of Chemistry, University of New South Wales, Sydney, NSW, 2052, Australia.

General Experimental 2Synthesis of the ionic liquids 3-9 and 11 3NMR spectra of the ionic liquids 3-9 and 11 8Kinetic analyses 15Rate data for the mole fraction dependence plots shown in Figures 3 and 5 16The mole fraction dependence plot for the ionic liquid [bmim][OTf] 6 23Eyring plot for the data shown in Table 1 in the main text 24Rate data for the Eyring plot shown in Figure S2 25

Determination of the N parameter for ionic liquids 9 and 11 30

Attempted correlation of activation parameters with Kamlet-Taft and N parameter 32References 34

1

Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry.This journal is © The Royal Society of Chemistry 2018

General Experimental

1-Fluoro-2,4-dinitrobenzene 1 was used as received without further purification. Ethanol

was purified through distillation from magnesium and iodine, and triethylamine was purified

through distillation from calcium hydride.1 Each of the ionic liquids 3-9 and 11 were

synthesised, through alkylation of N-methylimidazole to give ionic liquids 3 and 4, then

subsequent anion metathesis to the desired ionic liquids 5-9 and 11. Ionic liquid [TOA]Br 13

was commercially available and was purified through recrystallisation from ethyl acetate.

Before use, each of the ionic liquids was dried under reduced pressure for at least 3 hours;

resulting in them having < 200 ppm water (except ionic liquid 6, with 500 ppm water) as

determined using Karl Fischer titrimetry. Ionic liquids 6-11 had < 0.4 mol% residual halide

determined using ion chromatography.

Where mentioned, in vacuo refers to the use of a Heidolph ‘Hei-vap precision’ rotary

evaporator connected to a Vacuubrand PC500 series pump unit. The phrase ‘under reduced

pressure’ refers to use of a Schlenk line, connected to an Edwards oil pump with a measured

vacuum of < 0.1 mbar.1H, 13C and 19F NMR spectra for characterisation of synthesised ionic liquids were

carried out on either a Bruker Avance III 300, Bruker Avance III 400, Bruker Avance III

400 HD or a Bruker Avance III 600 HD with a BBFO, BBO or TCI probe. NMR spectra

used for characterisation were processed using the Bruker TOPSPIN 3.5 - 4.0 software. 19F

NMR spectra were referenced to ,,-trifluorotoluene (neat, in capillary inserts). 19F NMR

kinetic experiments were carried out on either a Bruker Avance III 400, or Bruker Avance

III 600 spectrometer with a BBFO probe using ca. 0.5 mL of reaction mixture in a 5 mm

NMR tube. Results were shown to be reproducible between the spectrometers.

Ion chromatography measurements were carried out on a Metrohm 883 Basic IC plus

with an eluent of aqueous carbonate/hydrogen carbonate (3.5 mM, pH 6.4). Data was

handled with MagIC Net 2.1 software.

2

Synthesis of the ionic liquids 3-9 and 11

1-Butyl-3-methylimidazolium chloride 3

n-Chlorobutane (81.0 mL, 0.770 mol) was added to N-methylimidazole (49.2 g, 0.599 mol)

and the resulting mixture was stirred at 60 °C under a nitrogen atmosphere for 14 days.

During this time two layers formed. The resulting viscous liquid was triturated with ethyl

acetate (7 x 200 mL) and any residual solvent was removed under reduced pressure to yield

the chloride salt 3 as a white solid (103 g, 0.589 mol, 98%). m.p. 63-67 °C (lit.2 65 °C). 1H

NMR (300 MHz, d3-acetonitrile) δ 0.92 (t, J = 7.2 Hz, 3H, CH2CH3), 1.30 (m, 2H,

CH3CH2), 1.82 (m, 2H, NCH2CH2CH2CH3), 3.89 (s, 3H, N(CH3), 4.21 (t, J = 7.3 Hz, 2H,

NCH2CH2CH3), 7.50 (m, 2H, NCHCHN), 9.76 (s, 1H, NCHN).

1-Butyl-3-methylimidazolium bromide 4

n-Bromobutane (133 mL, 1.23 mol) was added to N-methylimidazole (50.7 g, 0.617 mol)

and the resulting mixture was stirred at room temperature under a nitrogen atmosphere for 4

days. During this time two layers formed. The resulting viscous liquid was triturated with

ethyl acetate (7 x 200 mL) and during these washes a white precipitate formed. The solid

was crushed and any residual solvent was removed under reduced pressure to yield the

bromide salt 4 as a white solid (121 g, 0.552 mol, 89%). m.p. 68-70 °C (lit.3 70 °C). 1H

NMR (300 MHz, d3-acetonitrile) δ 0.94 (t, J = 7.4 Hz, 3H, CH2CH3), 1.26 – 1.39 (m, 2H,

CH3CH2), 1.76 – 1.86 (m, 2H, NCH2CH2CH2CH3), 3.84 (s, 3H, N(CH3), 4.15 (t, J = 7.3 Hz,

2H, NCH2CH2CH3), 7.35 – 7.40 (m, 2H, NCHCHN), 8.74 (s, 1H, NCHN).

3

1-Butyl-3-methylimidazolium dicyanimide 5

A mixture of sodium dicyanimide (23.6 g, 0.265 mol) in acetone (100 mL) was added to a

mixture of 1-butyl-3-methylimidazolium chloride 3 (43.8 g, 0.251 mol) in acetone (100 mL)

and the resulting mixture was stirred at room temperature for 21 hours. The mixture was

filtered and the acetone was removed in vacuo. The resultant colourless liquid was dissolved

in dichloromethane (150 mL) and a white precipitate formed; this mixture was stored at

-20 °C overnight. This process was repeated eight times until the chloride content of the

ionic liquid was < 0.2 mol%. The remaining solution was dried under reduced pressure to

yield the salt 5 as a pale yellow, viscous liquid (27.8 g, 0.135 mol, 54%). 1H NMR (300

MHz, d3-acetonitrile) δ 0.94 (t, J = 7.4 Hz, 3H, CH2CH3), 1.31 (m, 2H, CH3CH2), 1.81 (m,

2H, NCH2CH2CH2CH3), 3.82 (s, 3H, NCH3), 4.12 (t, J = 7.3 Hz, 2H, NCH2CH2CH2CH3),

7.34 - 7.38 (m, 2H, NCHCHN), 8.45 (s, 1H, NCHN). 13C NMR (75 MHz, d3-acetonitrile) δ

13.7 (CH2CH3), 19.9 (CH2CH3), 32.5 (NCH2CH2), 36.7 (NCH2CH2), 50.1 (NCH3), 120.5

(N(CN)2), 123.2 (NCHCHN), 124.5 (NCHCHN), 137.1 (NCHN).

4

1-Butyl-3-methylimidazolium trifluoromethanesulfonate 6

Ionic liquid 6 was synthesised with reference to the literature procedure from Li et al.4 A

mixture of aqueous hydrogen peroxide (25%,i 9.69 g, 0.0703 mol) and

trifluoromethanesulfonic acid (21.1 g, 0.141 mol) was added dropwise over 10 minutes to a

mixture of 1-butyl-3-methylimidazolium bromide 4 (30.8 g, 0.141 mol) and 1-hexene (25

mL). During this time, the white solid disappeared and two layers formed. The bottom layer

became dark orange and this mixture was stirred at room temperature for 4 hours. The

solution slowly changed colour from the orange, to yellow, and then colourless in this time.

The ionic liquid layer was extracted with hexane (3 x 50 mL) and was then repeatedly dried

under reduced pressure (ca. 6 hours x 6) until the residual bromide content of the ionic

liquid detected using ion chromotography was < 0.4 mol% and the residual acid content was

< 1.0 mol% (determined from titration against sodium hydroxide). This process gave the

ionic liquid 6 as a brown liquid (31.8 g, 0.110 mol, 78%). 1H NMR (300 MHz,

d6-dimethylsulfoxide) δ 0.90 (t, J = 7.4 Hz, 3H, CH2CH3), 1.22 - 1.30 (m, 2H, CH3CH2),

1.71 - 1.81 (m, 2H, NCH2CH2CH2CH3), 3.84 (s, 3H, NCH3), 4.16 (t, J = 7.2 Hz, 2H,

NCH2CH2CH2CH3), 7.68 - 7.76 (m, 2H, NCHCHN), 9.09 (s, 1H, NCHN). 13C NMR (150

MHz, d6-dimethylsulfoxide) δ 13.4 (CH2CH3), 19.0 (CH2CH3), 31.6 (NCH2CH2), 35.9

(NCH2CH2), 48.8 (NCH3), 120.9 (q, JCF = 324 Hz, SO3CF3), 122.4 (NCHCHN), 123.8

(NCHCHN), 136.6 (NCHN).

i Based on titration against potassium permanganate.

5

1-Butyl-3-methylimidazolium tetrafluoroborate 7

A mixture of sodium tetrafluoroborate (22.0 g, 0.200 mol) in acetone (100 mL) was added to

a mixture of 1-butyl-3-methylimidazolium chloride 3 (33.3 g, 0.190 mol) in acetone (100

mL) and the resulting mixture was stirred at room temperature for 18 hours. The sodium

chloride that precipitated was removed via filtration and the acetone was removed in vacuo.

Dichloromethane (150 mL) was then added to the reaction and the mixture was stored at -20

°C overnight. The sodium chloride that precipitated was then removed via filtration and the

dichloromethane was removed in vacuo. Dichloromethane (150 mL) was added again and

the process was repeated nine more times until < 0.1 mol% chloride of the ionic liquid was

determined using ion chromatography. The dichloromethane was removed in vacuo and the

residue was dried under reduced pressure to give the ionic liquid 7 as a light yellow, viscous

liquid (38.1 g, 0.169 mol, 89%). 1H NMR (400 MHz, d3-acetonitrile) δ 0.94 (t, J = 7.4 Hz,

3H, CH2CH3), 1.31 (m, 2H, CH3CH2), 1.80 (m, 2H, NCH2CH2CH2CH3), 3.82 (s, 3H,

NCH3), 4.12 (t, J = 7.3 Hz, 2H, NCH2CH2CH2CH3), 7.33 - 7.37 (m, 2H, NCHCHN), 8.41 (s,

1H, NCHN). 19F NMR (376 MHz, d3-acetonitrile) δ -150.85 (s, 0.8F, 10BF4), -150.91 (s,

3.2F, 11BF4).ii

1-Butyl-3-methylimidazolium hexafluorophosphate 8

A solution of potassium hexafluorophosphate (54.5 g, 0.296 mol) in water (100 mL) was

added to a solution of 1-butyl-3-methylimidazolium bromide 4 (36.7 g, 0.167 mol) in water

(100 mL). Immediately two layers formed and the mixture was stirred at room temperature

for 24 hours. Dichloromethane (50 mL) was added, the mixture separated and the aqueous

layer was extracted with dichloromethane (3 x 50 mL). The combined organic layers were

then repeatedly washed with water (15 x 150 mL). The dichloromethane was removed under

reduced pressure to yield the salt 8 as a colourless, viscous liquid (33.4 g, 0.118 mol, 70%). 1H NMR (300 MHz, d3-acetonitrile) δ 0.92 (t, J = 7.3 Hz, 3H, CH2CH3), 1.28 - 1.35 (m, 2H,

CH3CH2), 1.76 - 1.83 (m, 2H, NCH2CH2CH2CH3), 3.82 (s, 3H, NCH3), 4.12 (t, J = 7.3 Hz,

2H, NCH2CH2CH2CH3), 7.33 - 7.38 (m, 2H, NCHCHN), 8.39 (s, 1H, NCHN). 19F NMR

(376 MHz, d3-acetonitrile) δ -72.2 (d, JFP = 706 Hz, PF6).

ii The two signals result from an isotope chemical shift in a ratio of 1:4 corresponding to the natural abundances of the two isotopes of boron (10B and 11B, respectively).

6

1-Butyl-3-methylimidazolium bis(fluorosulfonyl)imide 9

A solution of 1-butyl-3-methylimidazolium bromide 4 (42.2 g, 0.193 mol) in water (100

mL) was added to a solution of potassium bis(fluorosulfonyl)imide (47.4 g, 0.216 mol) in

water (100 mL). Immediately two layers formed and the mixture was stirred at room

temperature for 24 hours. Dichloromethane (50 mL) was added and the mixture was

repeatedly washed with water (10 x 100 mL). The dichloromethane was removed from the

organic layer under reduced pressure to yield the salt 9 as a colourless, viscous liquid

(51.6 g, 0.162 mol, 84%). 1H NMR (300 MHz, d3-acetonitrile) δ 0.94 (t, J = 7.3 Hz, 3H,

CH2CH3), 1.26 - 1.39 (m, 2H, CH3CH2), 1.75 - 1.85 (m, 2H, NCH2CH2CH2CH3), 3.81 (s,

3H, NCH3), 4.12 (t, J = 7.3 Hz, 2H, NCH2CH2CH2CH3), 7.32 - 7.36 (m, 2H, NCHCHN),

8.38 (s, 1H, NCHN). 19F NMR (376 MHz, d3-acetonitrile) δ 51.9 (N(SO2F)2).

1-Butyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide 11

A solution of 1-butyl-3-methylimidazolium chloride 3 (20.3 g, 0.116 mol) in water (100

mL) was added to a solution of lithium bis(perfluoroethylsulfonyl)imide (49.3 g, 0.127 mol)

in water (100 mL). Immediately two layers formed and the mixture was stirred at room

temperature for 24 hours. Dichloromethane (50 mL) was added and the mixture was

repeatedly washed with water (10 x 100 mL). The dichloromethane was removed from the

organic layer under reduced pressure to yield the salt 11 as a colourless, viscous liquid

(56.8 g, 0.109 mol, 94%). 1H NMR (400 MHz, d3-acetonitrile) δ 0.94 (t, J = 7.4 Hz, 3H,

CH2CH3), 1.28 - 1.37 (m, 2H, CH3CH2), 1.76 - 1.84 (m, 2H, NCH2CH2CH2CH3), 3.81 (s,

3H, NCH3), 4.11 (t, J = 7.4 Hz, 2H, NCH2CH2CH2CH3), 7.32 - 7.36 (m, 2H, NCHCHN),

8.38 (s, 1H, NCHN). 13C NMR (150 MHz, d3-acetonitrile) δ 13.6 (CH2CH3), 20.0

(CH2CH3), 32.6 (NCH2CH2), 36.8 (NCH2CH2), 50.3 (NCH3), 112.7 (tq, JCF = 293, 38 Hz,

N(SO2CF2CF3)2), 119.2 (qt, JCF = 288, 33 Hz, N(SO2CF2CF3)2), 123.3 (NCHCHN), 124.7

(NCHCHN), 136.9 (NCHN).

7

NMR spectra of the ionic liquids 3-9 and 11

1-Butyl-3-methylimidazolium chloride 3

N.B. Water signal at 2.70.

1-Butyl-3-methylimidazolium bromide 4

N.B. Water signal at 2.15

8

1H (d3-acetonitrile)


1-Butyl-3-methylimidazolium dicyanimide 5


9


13C (d3-acetonitrile)

1-Butyl-3-methylimidazolium trifluoromethanesulfonate 6


10

1H (d6-dimethylsulfoxide)

13C (d6-dimethylsulfoxide)

1-Butyl-3-methylimidazolium tetrafluoroborate 7


N.B. Externally referenced to -trifluorotoluene at -63.72.

11


19F (d3-acetonitrile)

1-Butyl-3-methylimidazolium hexafluorophosphate 8


N.B. Externally referenced to -trifluorotoluene at -63.72.

12



1-Butyl-3-methylimidazolium bis(fluorosulfonyl)imide 9


N.B. Externally referenced to -trifluorotoluene at -63.72

13



1-Butyl-3-methylimidazolium bis(perfluoroethylsulfonyl)imide 11


14


13C (d3-acetonitrile)

Kinetic analyses

Examining the kinetics of the nucleophilic aromatic substitution reaction (Scheme 1) between

1-fluoro-2,4-dinitrobenzene 1 and ethanol, in the ionic liquids 3-9, 11, 13 and LiBr

To determine the rate constants of the reaction of ethanol with benzene 1 in mixtures

containing different amounts of each of the ionic liquids 3-8, 13 and lithium bromide salt,

standard solutions were prepared containing triethylamine (ca. 0.35 mol L-1) and varying

concentrations of ethanol dissolved in one of the ionic liquids 3-8, 13 and lithium bromide

salt to each desired mole fraction (see Tables S1-S8).

To determine the activation parameters for the ionic liquid solvents 3-9, 11-13 and

lithium bromide salt, standard solutions were prepared containing triethylamine (ca. 0.35

mol L-1) and ethanol dissolved in one of the ionic liquids 3-9, 11-13 and lithium bromide

salt at the desired mole fraction to a total volume of 10 mL (see Tables S9-S17 for exact

amounts).

The probe in the NMR spectrometer was equilibrated to the desired temperature.

1-Fluoro-2,4-dinitrobenzene 1 (ca. 3 mg, 0.02 mmol) was added to a 5 mm NMR tube

followed by an aliquot of a standard solution (0.50 mL). Reaction progress was followed

using 19F NMR spectroscopy to observe the depletion of the starting material 1 signal at δ

ca. -110. The pseudo first order rate constant (kobs) and, using the concentration of ethanol,

the second order rate constant (k2) were determined from the change in integration of this

signal. These data were used in the bimolecular form of the Eyring equation to create an

Eyring plot (see Figure S2) and calculate the activation parameters in each case.

15

Rate data for the mole fraction dependence plots shown in Figures 3 and 5

Table S1. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [bmim]Cl 3 at 324 K.

16

Masses Concentrations Rate constantsIL

3IL/ g

NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]/ mol L-1

kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

6.43 0.4326.16 0.4140.0318 0.175 0.0753 1.37 0.372 14.96.10 0.40410.4 0.80711.1 0.8600.0862 0.435 0.0711 1.18 0.351 12.911.7 0.90815.3 1.40

0.150 0.694 0.0726 1.01 0.359 10.913.2 1.2116.1 1.7117.3 1.830.200 0.861 0.0809 0.871 0.400 9.4515.3 1.6218.3 2.2117.9 2.170.252 1.01 0.0716 0.763 0.354 8.2816.6 2.0119.9 2.8319.2 2.730.310 1.16 0.0732 0.649 0.362 7.0519.8 2.8121.5 3.3920.5 3.220.348 1.25 0.0725 0.585 0.358 6.3519.9 3.1420.6 3.8522.1 4.140.410 1.38 0.0712 0.492 0.352 5.3423.3 4.3622.0 4.6825.4 5.390.454 1.47 0.0759 0.433 0.375 4.7025.6 5.4526.0 5.8926.5 6.010.475 7.53 0.353 2.03 0.348 4.4225.5 5.76

Table S2. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [bmim]Br 4 at 324 K.

17


4IL/ g

NEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

4.54 0.3024.64 0.3080.0290 0.202 0.0706 1.39 0.349 15.14.97 0.3307.46 0.5387.89 0.5690.0570 0.378 0.0798 1.28 0.394 13.97.87 0.56810.2 0.90311.2 0.9890.132 0.779 0.0775 1.04 0.383 11.310.0 0.88711.7 1.2512.5 1.340.188 0.982 0.0722 0.857 0.357 9.3011.6 1.25

Table S3. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [bmim][N(CN)2] 5 at 324 K.

iii Duplicate mole fraction as these data are a subset of the temperature dependent data; solution was prepared to 10 mL rather than 2 mL.

18


5IL/ g

NEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

6.79 0.5696.49 0.5440.0970 0.542 0.0731 1.10 0.361 11.96.50 0.5459.30 1.078.43 0.9690.204 0.950 0.0705 0.802 0.348 8.708.51 0.97810.5 1.6011.1 1.690.297 1.21 0.0714 0.608 0.353 6.6013.8 2.0910.9 2.2711.2 2.350.402 1.42 0.0700 0.441 0.346 4.7910.2 2.1312.2 3.5413.3 3.850.504 1.59 0.0716 0.318 0.354 3.469.83 2.859.92 4.238.53 3.640.611 1.74 0.0704 0.216 0.348 2.348.43 3.607.93 5.146.22 4.030.701 1.82 0.0695 0.142 0.343 1.546.67 4.324.41 4.94

0.788 1.91 0.0715 0.0823 0.353 0.8935.37 6.014.79 5.634.39 5.160.795iii 9.52 0.353 0.392 0.349 0.8514.13 4.85

Table S4. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [bmim][OTf] 6 at 324 K.

19


6IL/ g

NEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

3.33 0.4035.01 0.6070.197 1.22 0.0733 0.761 0.362 8.262.91 0.3523.27 0.7233.33 0.7370.389 1.79 0.0721 0.417 0.356 4.533.31 0.7323.65 1.403.01 1.150.549 2.08 0.0714 0.240 0.353 2.613.04 1.162.48 1.762.33 1.650.687 2.23 0.0721 0.130 0.349 1.412.02 1.432.64 1.92

0.687 2.24 0.0803 0.127 0.397 1.382.26 1.64

Table S5. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [bmim][BF4] 7 at 324 K.

20


7IL/ g

NEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

7.05 1.086.83 1.050.307 1.38 0.0719 0.601 0.355 6.538.19 1.257.33 1.507.17 1.470.404 1.61 0.0717 0.450 0.354 4.887.65 1.576.86 1.867.05 1.920.494 1.78 0.0710 0.339 0.351 3.686.69 1.826.20 2.386.25 2.400.590 1.93 0.0711 0.240 0.351 2.615.94 2.284.65 2.844.29 2.620.694 2.04 0.0720 0.151 0.356 1.644.40 2.68

Table S6. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [bmim][PF6] 8 at 324 K.

21


8IL/ g

NEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

6.54 1.435.29 1.150.401 1.88 0.0703 0.422 0.347 4.585.06 1.105.81 1.735.52 1.640.495 2.06 0.0706 0.310 0.349 3.365.27 1.576.54 2.726.06 2.520.585 2.22 0.0733 0.222 0.362 2.416.41 2.665.36 3.675.63 3.850.694 2.36 0.0735 0.135 0.363 1.465.22 3.574.19 5.523.62 4.770.798 2.49 0.0709 0.0699 0.350 0.7593.33 4.38

Table S7. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing [TOA]Br 13 at 324 K.

Table S8. Masses used to prepare reaction mixtures, mole fraction of ionic liquid and concentrations of reagents in the reaction mixture, and rate constants for the reaction between1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in mixtures containing lithium bromide at 324 K.

22


13IL/ g

NEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

3.00 0.1962.83 0.1850.00634 0.109 0.0711 1.41 0.351 15.33.14 0.2056.32 0.5207.19 0.5920.0323 0.457 0.0714 1.12 0.353 12.27.97 0.65611.1 1.3310.1 1.210.0770 0.795 0.0712 0.770 0.352 8.3610.9 1.3010.8 1.5010.5 1.460.108 1.00 0.0715 0.663 0.353 7.2010.7 1.4913.7 2.5012.2 2.230.159 1.20 0.0708 0.503 0.350 5.4612.2 2.24

Masses Concentrations Rate constantsSALT SALT

/ gNEt3

/ gEtOH

/ g[NEt3]


kobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

12.8 0.8008.44 0.5270.0287 0.0840 0.0762 1.48 0.377 16.011.7 0.72820.3 1.3024.7 1.580.0626 0.186 0.0791 1.44 0.391 15.624.6 1.5841.2 2.6839.0 2.540.100 0.305 0.0717 1.42 0.354 15.430.6 1.99

The mole fraction dependence plot for the ionic liquid [bmim][OTf] 6

Figure S1. The dependence of the bimolecular rate constant on the mole fraction of the ionic liquid [bmim][OTf] 8 () in the reaction mixture. Uncertainties are the standard deviation of triplicate measurements; some uncertainties are smaller than the marker used.

23

Eyring plot for the data shown in Table 1 in the main text

Figure S2. The Eyring plot for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol in mixtures containing either [bmim]Cl 4 (), [bmim]Br 5 (), [bmim][N(CN)2] 6 (), [bmim][BF4] 7 (), [bmim][OTf] 8 (), [bmim][PF6] 9 (), [bmim][N(SO2F)2] 10 (), [bmim][N(SO2CF2CF3)2] 11 (), [TOA]Br 13 () or lithium bromide () in ethanol at the highest mole fraction used.

24

Rate data for the Eyring plot shown in Figure S2

Table S9. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim]Cl 3 (IL = 0.475).

Table S10. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim]Br 4 (IL = 0.174).

25

Masses Concentrations Rate constantsIL / g

NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]

/ mol L-1Temperature

/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

2.98 0.6753.04 0.688

294.1294.0294.0 2.96 0.671304.0 6.08 1.38304.0 5.85 1.32304.1 6.50 1.47314.0 13.1 2.98314.0 13.4 3.03314.0 12.7 2.88324.0 26.0 5.89324.0 26.5 6.01

7.53 0.353 2.04 0.348 4.42

324.0 25.5 5.76

Masses Concentrations Rate constantsIL/ g

NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

3.52 0.3463.64 0.358

304.0304.0304.0 3.18 0.313314.1 6.08 0.598314.0 6.68 0.657314.1 6.10 0.600324.0 11.5 1.14324.0 12.5 1.23324.0 11.5 1.13334.0 24.6 2.42334.0 22.2 2.19

4.87 0.351 4.68 0.347 10.2

334.0 22.2 2.19

Table S11. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim][N(CN)2] 5 (IL = 0.795).

Table S12. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim][OTf] 6 (IL = 0.833).

26


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

2.09 2.452.84 3.34

314.0314.0314.1 2.45 2.88324.0 4.79 5.63324.0 4.39 5.16324.0 4.13 4.85334.0 6.21 7.29334.0 7.14 8.39334.0 7.11 8.35344.0 12.8 15.1344.0 13.7 16.1

9.52 0.353 0.392 0.349 0.851

344.0 10.2 12.0


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

0.600 1.250.532 1.11

314.0314.0314.1 0.551 1.15324.0 0.970 2.02324.0 0.884 1.84324.1 0.810 1.69334.0 1.70 3.55334.0 1.46 3.03334.0 1.39 2.89344.0 2.98 6.21344.0 2.29 4.78

12.0 0.354 0.221 0.349 0.480

343.9 2.14 4.45

Table S13. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim][BF4] 7 (IL = 0.585).

Table S14. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim][PF6] 8 (IL = 0.792).

27


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

1.71 0.6461.52 0.576

304.0304.0304.0 1.63 0.617314.1 3.48 1.32314.0 4.07 1.54314.1 3.50 1.33324.0 6.18 2.33324.0 6.25 2.36324.0 6.60 2.49334.0 11.9 4.50334.0 12.8 4.85

9.64 0.339 1.22 0.345 2.65

334.0 11.3 4.26


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

2.48 3.232.59 3.38

314.0314.0314.1 2.49 3.25324.0 4.86 6.34324.0 3.98 5.20324.0 4.27 5.57334.0 7.68 10.0334.0 8.14 10.6334.0 7.48 9.77344.0 12.8 16.8344.0 15.7 20.5

12.4 0.353 0.353 0.349 0.766

344.0 15.5 20.2

Table S15. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim][N(SO2F)2] 9 (IL = 0.811).

Table S16. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [bmim][N(SO2CF2CF3)2] 11 (IL = 0.789).

28


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

1.72 3.061.66 2.96

314.0314.1314.1 1.59 2.84324.1 2.75 4.89324.1 2.64 4.70324.0 2.72 4.84334.1 4.63 8.24334.0 4.77 8.49334.0 4.08 7.25344.0 7.86 14.0344.1 7.79 13.9

12.5 0.352 0.259 0.348 0.562

343.9 7.17 12.8


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

1.32 3.541.17 3.14

314.1314.1314.0 1.18 3.16324.1 2.26 6.05324.1 2.23 5.98324.0 2.21 5.92334.0 3.78 10.1334.0 3.26 8.74334.0 3.48 9.32344.0 5.75 15.4344.1 5.72 15.3

14.0 0.354 0.172 0.350 0.374

343.9 5.46 14.6

Table S17. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in [TOA]Br 13 (IL = 0.158).

Table S18. Masses used to prepare reaction mixtures, concentrations of reagents in the reaction mixture, and rate constants for the reaction between 1-fluoro-2,4-dinitrobenzene 1 and ethanol (Scheme 1) in lithium bromide (IL = 0.133).

29


NEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

1.31 0.2411.22 0.225

294.1294.0294.0 1.21 0.223304.0 2.73 0.501304.0 3.11 0.572304.1 3.05 0.560314.0 5.65 1.04314.0 6.18 1.14314.0 6.07 1.11324.0 11.0 2.02324.0 10.9 2.00

5.98 0.351 2.51 0.347 5.45

324.0 12.1 2.22

Masses Concentrations Rate constantsSALT

/ gNEt3

/ gEtOH

/ g[NEt3]

/ mol L-1[EtOH]


/ Kkobs

/ 10-4 s-1k2

/ 10-4 L mol-1 s-1

9.82 0.6317.91 0.508

294.1294.1294.0 5.45 0.350294.1 6.44 0.414304.1 15.1 0.972304.1 15.5 0.996304.0 16.9 1.09314.0 20.6 1.32314.0 39.0 2.51314.0 32.4 2.08314.0 33.2 2.14324.0 46.7 3.00324.0 79.0 5.07324.0 75.1 4.83

2.12 0.352 7.17 0.348 15.6

324.1 52.0 3.34

Determination of the N parameter for ionic liquids 9 and 11

The N parameter for ionic liquids 9, 10 and 11 were determined using 1H NMR

spectroscopy similarly to literature.5 Standard solutions were prepared containing one of the

ionic liquids 9, 10 and 11 in d2-dichloromethane (ca. 1.8 mol L-1, Table S19). The 1H NMR

spectra are presented below (Figures S3-S5).

Table S19. The masses and concentrations used for the standard solutions to determine the

N parameter for ionic liquids 3, 11 and 12.

MassesIonic liquid

Ionic liquid / g CD2Cl2 / g

[Ionic liquid]

/ mol L-1

C2-1H shift

of cationN

9 0.757 0.654 1.80 8.56 0.67

10 0.580 0.796 1.81 8.46 0.65

11 0.934 0.531 1.80 8.58 0.67

Figure S3. The 1H NMR spectrum for ionic liquid 10 in d2-dichloromethane.

30



31

Attempted correlation of activation parameters with Kamlet-Taft and N parameter

The activation parameters for the reaction between ethanol and the benzene 1 plotted against either

the Kamlet-Taft parameter or the N parameter of the ionic liquid used are presented below

(Figures S6 and S7).

Figure S6. Plots of the enthalpy and entropy of activation of the reaction between ethanol and the

benzene 1 against the Kamlet-Taft parameter at ca. 0.5-0.6 () and also ca. 0.8 ().

Figure S7. Plots of the enthalpy and entropy of activation of the reaction between ethanol and the

benzene 1 the N parameter at ca. 0.5-0.6 () and also ca. 0.8 ().

No correlation is observed between the activation parameters of the reaction being examined and

the N parameter of the ionic liquid at either of the mole fractions of the salt in the reaction mixture

that were considered above. The same is observed for the medium mole fraction ( ca. 0.5-0.6)

when plotted against the parameter. There is more of a trend at the higher mole fraction ( ca.

32

0.8) when plotted against the parameter however with only three points, and two being close

together, it would be inappropriate to call this a correlation.

33

References

1. W. L. F. Armarego and C. L. L. Chai, Purification of Laboratory Chemicals, Butterworth-Heinemann, Oxford, 2013.

2. Q. Q. Baltazar, S. K. Leininger and J. L. Anderson, J. Chromatogr. A, 2008, 1182, 119-127.3. A. Berthod, J. J. Kozak, J. L. Anderson, J. Ding and D. W. Armstrong, Theor. Chem. Acc.,

2007, 117, 127-135.4. W. Li, S. Dai, D. Li, Q. Zhang, H. Fan, T. Zhang and Z. Zhang, Synthesis, 2017, 49, 1065-

1072.5. R. Lungwitz and S. Spange, New J. Chem., 2008, 32, 392-394.

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