Electronic upplementary Material (EI) for Green Chemistry. This journal is The Royal ociety of Chemistry 205 Electronic upplementary Information A Class of Efficient hort-chain luorinated Catanionic urfactants P. Verdia, H. Q.. Gunaratne, T. Y. Goh, J. Jacquemin, and M. Blesic* The QUILL Research Centre, chool of Chemistry and Chemical Engineering, The Queen s University Belfast, tranmillis Road, Belfast BT9 5AG, United Kingdom. m.blesic@qub.ac.uk
Materials and methods Ethylene carbonate (CA 96-49-, Aldrich, 98%), tetraethylammonium iodide ( CA 68-05-3, Aldrich, 98%), H,H-nonafluoropentan--ol (CA 355-28-2, Apollo cientific, 97%), H,H-nonafluorohexan--ol (CA 423-46-, Apollo cientific, 98%), H,H-nonafluoroheptan--ol (CA 375-82-6, Apollo cientific, 97%), 2,2,3,3,4,4,5,5-octafluoropentan--ol (CA 355-80-6, Apollo cientific, 98%), trimethylamine (CA 2-44-8, igma Aldrich, 99%), methanesulfonyl chloride (CA 24-63-0, Aldrich, 98%), -methylimidazole (CA 66-47- 7, Aldrich, 99%),,-dimethylethylamine (CA 598-56-, Aldrich, 99%), sodium tert-butoxide (CA 865-48-5, Aldrich, 97%), and,3-propanesultone (CA 20-7-4, Aldrich, 98%) were used without further purification. Tetrahydrofuran was dried over sodium wire prior to use. H MR and 3 C MR spectra were recorded on a Bruker Avance III 400MHz spectrometer. EM-mass spectroscopy measurements were carried out on a Waters LCT Premier instrument with an Advion TriVersa anomate injection system (cone voltage 50 V, source 20 C). Both positive and negative ions were detected, with an m/z range of 50 to 500. amples were injected as dilute solutions in acetonitrile. All DC scans (for melting point measurements) were obtained using a TA DC Q2000 model with a TA Refrigerated Cooling ystem 90 (RC). or each sample, three scans were run with scan rates of 5 o C min -. General procedures for the synthesis of fluorosurfactants (-5) All surfactants were synthesised according to the synthetic scheme given below: (C 2 H () a; =, n = 5 b; =, n = 4 c; =, n = 3 (C 2 H (2) a; =, n = 5 b; =, n = 4 c; =, n = 3 Cl (C 2 (4) a; =, n = 5 b; =, n = 4 c; =, n = 3 + (C 2 (3) a; =, n = 5 b; =, n = 4 c; =, n = 3 (C 2 + (5) = H, n = 3 atbu (C 2 H propanesultone () a; =, n = 5 b; =, n = 4 c; =, n = 3 (C 2 (6) a; =, n = 5 b; =, n = 4 c; =, n = 3 - a+ Metathesis: (4a); =, n = 5 + (4b); =, n = 4 + (4c); =, n = 3 + (4d); = H, n = 3 + (5); = H, n = 3 + (6a); =, n = 5 (6b); =, n = 4 (6c); =, n = 3 (6d); = H, n = 3 (6d); = H, n = 3 : [C 6 3 mim][c 6 3 ] 2: [C 5 mim][c 5 ] 3: [C 4 9 mim][c 4 9 ] 4: [HC 4 8 mim][hc 4 8 ] 5: [HC 4 8 2 ][HC 4 8 ] cheme EI: ynthetic scheme for fluorosurfactants
tep : + + Et 4 I 40 C C H n 2n+ C n 2n+ H A chlenk tube connected to a bubbler was charged with a fluorinated alcohol ( eq.), ethylene carbonate (2 eq.) and a catalytic amount of tetraethylammonium iodide (2 mol% with respect to alcohol). The reaction mixture was stirred and heated at 40 C for 48 h. The resulting product was poured into water and extracted into ether. The ether extract was washed twice with water and dried over anhyd. Mg 4. Then, ether was removed from the extract on rotary evaporator. The crude product was distilled under high vacuum to yield the required product as the major fraction. tep 2: H CH 3 2 Cl C n 2n+ + + Et 3 C n 2n+ DCM In a round bottom flask fluorinated oxy-alcohol ( eq.) and Et 3 (. eq.) were added to dry dichloromethane and cooled in ice. To this solution methanesulfonyl chloride ( eq.) was added drop-wise. The reaction mixture was allowed to warm to room temperature and stirred overnight, then poured into water and shaken in a separating funnel. DCM layer was washed with 2 HCl and dried over anhyd. Mg 4. Removal of the solvent under high vacuum gave the desired product in a good yield. tep 3: C n 2n+ + C n 2n+ + luorinated sulfonate ester ( eq.) and -methylimidazole ( eq.) in DCM were heated in a screw-cap tube at 50 C for 24h. Removal of the solvent under high vacuum yielded the desired product (4) in near quantitative yield. A similar procedure was adapted for the reaction involving dimethylethylamine to yield the corresponding tetraalkylammonium methanesulfonate (5). General procedure for the synthesis of sodium salts of fluorinated sulfonates The appropriate fluorinated alcohol ( eq.) was added at 0 C in a suspension of sodium tert-butoxide (. eq.) in dry TH. Mixture was allowed to stir for 30 min., and then a solution of,3-propanesultone in dry TH was added dropwise. The reaction mixture was allowed to warm up to r.t. and finally heated at 55 C overnight. After removal of the solvent, the crude residue was purified by flash column chromatography (Hexane:AcEt = :) to obtain pure (6). General procedure for cation-anion metathesis
The appropriate salt (4 or 5, 4 mmol) and the corresponding sodium salt of fluorinated sulfonate (6, 4 mmol) were homogenised with deionised water (0.3 ml) and then extracted into organic solvent. The obtained extract was dried with anhyd. Mg 4. Removal of the solvent under high vacuum yielded the desired catanionic surfactants (-5) in high yields. ee Table for analytical data. Table EI: H and 9 MR, EM, and melting temperature or glass transition data for the synthesised fluorosurfactants. urfactant MR data (400 MHz) EM Melting point/glass transition [C 6 3 mim][ C 6 3 ] H(dmso-d 6 ): 9.2(s, H, Im-H), 7.72(2xs, 2H, Im-H), 4.4(t, 2H, CH 2 ), 4.25(t, 2H, CH 2 ), 4.0(t, 2H, CH 2 ), 3.97(t, 2H, CH 2 ), 3.85(s, 3H, -CH 3 ), 3.63(t, 2H, CH 2 ), 2.43(t, 2H,CH 2 ),.8(q, 2H,CH 2 ). Cation: calc. 459.0742 bserved, 459.0633 Anion: Calc. 470.9936 bserved, 470.9934 MP: - 2 o C 9 (dmso-d 6 ): -80.5(m, 2xC 3 ), 9.0(t, C 2 ), 9.2(t, C 2 ), 22.3(m, 2xC 2 ), 22.8(m, 2xC 2 ), 23.(m, 2xC 2 ), 26.0(m, 2xC 2 ). 2 [C 5 mim][ C 5 ] H(dmso-d 6 ): 9.8(s, H, Im-H), 7.78(2xs, 2H, Im-H), 4.49(t, 2H, CH 2 ), 4.32(t, 2H, CH 2 ), 4.7(t, 2H, CH 2 ), 4.05(t, 2H, CH 2 ), 3.93(s, 3H, -CH 3 ), 3.7(t, 2H, CH 2 ), 2.50(t, 2H,CH 2 ),.89(q, 2H,CH 2 ). Cation: calc. 409.0536 bserved, 409.0720 Anion: Calc. 420.9968 bserved, 420.9978 GT: - 3 o C 9 (dmso-d 6 ): -80.3(m, 2xC 3 ), 8.9(t, C 2 ), 9.(t, C 2 ), 22.9(m, 2xC 2 ), 23.2(m, 2xC 2 ), 25.9(m, 2xC 2 ). 3 [C 4 9 mim][ C 4 9 ] H(dmso-d 6 ): 9.(s, H, Im-H), 7.73(s, H, Im-H), 7.7(s, H, Im-H), 4.42(t, 2H, CH 2 ), 4.25(t, 2H, CH 2 ), 3.99(t, 2H, CH 2 ), 3.98(m, 2H, CH 2 ), 3.86(s, 3H, -CH 3 ), 3.64(t, 2H, CH 2 ), 2.43(t, 2H,CH 2 ),.8(t, 2H,CH 2 ). Cation: calc.359.0806 bserved, 359.077 Anion: Calc.37.0020 bserved, 37.003 MP: 40 o C 9 (dmso-d 6 ): -80.6(m, 2xC 3 ), 9.2(t, C 2 ), 9.4(t, C 2 ), 23.9(m, C 2 ), 24.0(m, C 2 ), 26.2(m, 2xC 2 ) 4 [HC 4 8 mim][hc 4 8 ] H MR (300 MHz, CDCl3) δ: 9.90 (s, H), 7.37 (s, H), 7.9 (s, H), 6.29 5.83 (m, 2H), 4.6 (t, J = 4.5 Hz, 2H), 4.4 3.83 (m, 9H), 3.75 (t, J = 6.3 Hz, 2H), 2.98 2.8 (m, 2H), 2.4 (m, 2H), 2.04 (s, 3H). Cation: calc. 34.0900 bserved, 34.0872 Anion: Calc.353.0094 bserved, 353.0096 GT: - 7 o C 9 MR (282 MHz, CDCl3) δ: -20.39, -20.35, -25.84 (t, J = 7.4 Hz), -26.25 (t, J = 7.8 Hz), -30.4-30.66 (m), - 30.83-3.0 (m), -37.72 (s), -37.88 (s). 5 [HC 4 8 2 ][HC 4 8 ] H MR (400 MHz, CDCl 3 ) δ: 6.07 (m, 2H, CH 2 ), 4.8 (t, 2H, CH 2 ), 4.07 (t, 2H, CH 2 ), 3.92 (t, 2H, CH 2 ), 3.89(t, 2H), 3.73(t, 2H), 3.60(q, 2H, CH 2 Me), 3.26(s, 6H, Me 2 ), 2.86(t, 2H ), 2.09(m, 2H),.4(t, 3H, CH 2 CH 3 ). Cation: calc. 332.386 bserved, 332.223 Anion: Calc. 353.0094 bserved, 353.009 GT: - 8 o C 9 MR (CDCl 3 ) δ: -9.8(C 2 ), -9.9(C 2 ), -25.3 (C 2 ), - 25.8 (C 2 ), -30.0 (m, C 2 ), -30.5(m, C 2 ), 37.2 (m, C 2 ), 37.4(m, C 2 ).
Determination of critical micelle constant (CMC) by interfacial tension and by 9 MR spectroscopy: Measurement of interfacial tension (IT) Interfacial tension of aqueous surfactant solutions was measured using a Drop hape Analysis Tensiometer Kruss DA v.80 working in the pendant drop mode at a constant temperature of (23±0.5) o C. The needle diameter was chosen as a function of the maximisation of the scale of measurement. Brightness (contrast) was adjusted in order to minimise noise in the image acquisition and digitisation. IT is derived from the fit of the pendant drop profile, and care was taken to ensure that the apparatus was calibrated with several solvents of known IT in the range of interest. The drops were left to equilibrate close to the rupture point and at least three consistent measurements per solution were recorded. 9 MR spectroscopic analysis of the aggregation phenomena: The same aqueous surfactant solutions prepared for the surface tension measurement were used for obtaining 9 MR spectra with an external standard (LiTf 2 ) and a deuterium lock (D 2 ) contained in sealed capillary tube. All MR spectra were phase corrected manually, designating the chemical shift of C 3 groups in LiTf 2 to -80 ppm (igure 4 in main text). δ/ ppm 82.8 82.6 82.4 82.2 82 8.8 8.6 8.4 8.2 [C49mim][C49] 0 2 4 6 8 0 2 c / mm igure EI: 9 MR chemical shifts δ of the terminal -C 3 groups in the [C 4 9 mim][c 4 9 ] as a function the surfactant concentration. 0.7 0.6 0.5 [C5mim][C5] ν /2 / ppm 0.4 0.3 0.2 0. 0 0 0.2 0.4 0.6 0.8.2 c / mm igure 2 EI: Half line width Δν /2 of 9 MR chemical shifts for the terminal C 3 group in the [C 5 mim][c 5 ] as a function the surfactant concentration.
igure 3EI: Chemical structure of catanionic surfactant [C 8 H 7 mim][c 8 H 7 ].. M. Blesic, M. wadzba-kwasny, J. D. Holbrey, J.. C. Lopes, K. R. eddon and L. P.. Rebelo, Physical Chemistry Chemical Physics, 2009,, 4260-4268.