Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids As Lubricant Additives

Tertiary and Quaternary Ammonium-Phosphate Ionic Liquids as Lubricant Additives

Table S1. NMR spectra data of ionic liquids.

Ionic liquid / 1H NMR data / 13C NMR data
[N2222][DEHP] / 0.84-0.88 (m, 24H, 8CH3), 1.26-1.37 (m, 16H, 8CH2), 1.42 (m, 2H, 2CH), 3.44 (m, 8H, 4NCH2), 3.71 (m, 4H, 2OCH2); / 7.35 (4CH3), 10.69 (2CH3), 13.82 (2CH3), 22.84 (2CH2), 23.05 (2CH2), 28.76 (2CH2), 29.83 (2CH2), 40.12 (2CH), 52.10 (4NCH2), 67.14 (2OCH2).
[N4444][DEHP] / 0.86 (m, 6H, CH3), 0.88 (m, 6H, CH3), 0.98-1.02 (m, 12H, CH3), 1.24-1.27 (m, 12H, CH2), 1.32 (m, 2H, CH), 1.43-1.48 (m, 8H, CH2), 1.51 (m, 4H, CH2 ), 1.64 (m, 8H, CH2), 3.36 (t, 8H, NCH2), 3.70 (m, 4H, OCH2); / 10.98 (2CH3), 13.71 (2CH3), 14.15 (2CH3), 19.73 (4CH2), 23.18 (3CH2), 23.33 (3CH2), 24.07 (2CH), 29.08 (2CH3), 30.12 (2CH2), 40.41 (2CH2), 40.49 (2CH2), 58.72 (4CH2), 67.27 (CH2), 67.32 (CH2).
[N6666][DEHP] / 0.84-0.91 (m, 24H, 8CH3), 1.25-1.39 (m, 40H, 20CH2), 1.40 (m, 2H, 2CH), 1.65 (m, 8H, 4CH2), 3.36 (t, 8H, 4NCH2), 3.70 (m, 4H, 2OCH2); / 10.85 (2CH3), 13.76 (4CH3), 14.02 (2CH3), 22.05 (4CH2), 22.28 (2CH2), 23.21 (4CH2), 25.94 (4CH2), 28.97 (2CH2), 30.00 (4CH2), 31.16 (4CH2), 40.39 (2CH), 58.78 (4NCH2), 67.22 (2OCH2).
[N8888][DEHP] / 0.85-0.87 (m, 24H, 8CH3), 1.27-1.36 (m, 48H, 24CH2), 1.44 (m, 2H, 2CH), 1.67 (m, 8H, 4CH2) ,3.31 (m, 8H, 4NCH2), 3.80 (m, 4H, 2OCH2); / 10.81 (2CH3), 13.96 (4CH3), 14.02 (2CH3), 22.02 (4CH2), 22.52 (4CH2), 23.04 (2CH2), 23.09 (4CH2), 26.28 (4CH2), 28.92 (2CH2), 29.06 (4CH2), 29.87 (4CH2), 31.64 (4CH2), 40.09 (2CH), 58.84 (4NCH2), 67.82 (2OCH2).
[N8881][DEHP] / 0.85 (m, 6H, CH3), 0.88 (m, 9H, CH3), 1.23-1.27 (m, 30H, CH3 and CH2), 1.32 (m, 6H, CH2), 1.35 (m, 12H, CH2), 1.43 (m, 4H, CH2), 1.49 (m, 2H, CH), 1.58(m, 6H, CH2), 3.28(s, 3H, NCH3), 3.37 (t, 6H, NCH2), 3.72 (m, 4H, OCH2); / 10.22 (CH3), 14.26 (CH3), 14.37 (CH3), 22.59 (CH2), 22.80 (CH2), 23.40 (CH2), 23.59 (CH2), 26.55 (CH2), 29.25 (2CH2), 29.314(CH2), 29.41 (CH2), 30.36 (CH3), 31.88 (CH2), 40.63 (CH), 49.08 (CH2), 61.37 (CH3), 67.74 (CH2);
[N222H][DEHP] / 0.85-0.97 (m, 12H, 4CH3), 1.20-1.30 (m, 9H, 3CH3), 1.30-1.40 (m, 12H, 6CH2), 1.44 (m, 2H, 2CH), 2.91 (m, 6H, 3NCH2), 3.77 (m, 4H, 2OCH2); / 8.15 (2CH3), 10.51 (3CH3), 13.60 (2CH3), 22.94 (2CH2), 28.57 (2CH2), 29.70 (2CH2), 39.97 (2CH), 44.82 (3NCH2), 67.08 (2OCH2)
[N444H][DEHP] / 0.85-1.05 (m, 21H, 7CH3), 1.30-1.40 (m, 16H, 8CH2), 1.44 (m, 2H, 2CH), 1.71 (m, 6H, 3CH2)2.94 (m, 6H, 3NCH2), 3.79 (m, 4H, 2OCH2); / 9.69 (2CH3), 10.55 (3CH3), 13.67 (2CH3), 19.80 (3CH2), 22.98 (3CH2), 24.77 (2CH2), 28.64 (2CH2), 29.73 (2CH2), 40.02 (2CH), 51.13 (3NCH2), 67.21 (2OCH2).
[N666H][DEHP] / 0.82-1.00 (m, 21H, 7CH3), 1.30-1.40 (m, 24H, 12CH2), 1.45 (m, 2H, 2CH), 1.70 (m, 6H, 3CH2), 2.91 (m, 6H, 3NCH2), 3.78 (m, 4H, 2OCH2); / 10.66 (2CH3), 13.56 (3CH3), 13.79 (2CH3), 22.17 (3CH2), 22.94 (3CH2), 23.09 (2CH2), 26.35 (3CH2), 28.77 (2CH2), 29.85 (2CH2), 31.01 (3CH2), 40.16 (2CH), 51.52 (3NCH2), 67.34 (2OCH2).
[N888H][DEHP] / 0.85-0.97 (m, 21H, 7CH3), 1.27-1.36 (m, 46H, 23CH2), 1.44 (m, 2H, 2CH), 1.69 (m, 6H, 3CH2), 2.91 (m, 8H, 3NCH2), 3.77 (m, 4H, 2OCH2); / 10.72 (2CH3), 13.78 (3CH3), 13.85 (2CH3), 22.33 (3CH2), 22.89 (3CH2), 23.04 (2CH2), 23.15 (3CH2), 26.75 (3CH2), 28.88 (2CH2), 29.91 (3CH2), 31.46 (2CH2), 31.64 (3CH2), 40.22 (2CH), 51.55 (4NCH2), 67.39 (2OCH2).

IL Synthesis

Tetraethylammoniumdi(2-ethylhexyl)phosphate [N2222][DEHP]. A solution of [N2222]OH in methanol was prepared from 2 g of [N2222]Cl (1.2 mmol) using a DowexMonosphere 550A (OH) anion exchange resin. 3.87 g of HDEHP (1.2 mmol) were added to the [N2222]OH solution. The mixture was then stirred at room temperature for 6 h until the solution became neutral. The methanol and water were distilled off, and the product was dried at 70 °C under vacuum for 12 h to yield [N2222][DEHP]as a viscous liquid (5.15 g, 11.4 mmol, yield: 95%).The water content of [N2222][DEHP] was1.9%.

Tetrabutylammoniumdi(2-ethylhexyl)phosphate [N4444][DEHP]. This IL was prepared in the similar procedure as above from [N4444]Cl (2.78 g, 10.0mmol) and HDEHP (3.22 g, 10.0mmol).[N4444][DEHP] wasobtained as a colorlessviscousliquid (5.29 g, 9.4 mmol, yield: 94%).2.1.3. Tetrahexylammoniumdi(2-ethylhexyl)phosphate [N6666][DEHP]. This IL was prepared in the similar procedure as above from [N6666]Br (4.0 g, 9.2mmol) and HDEHP (2.97 g, 9.2mmol). [N6666][DEHP] was obtained as a viscous liquid (5.95 g, 8.8 mmol, yield: 96%). The water content of [N6666][DEHP] was0.8%.

Tetraoctylammoniumdi(2-ethylhexyl)phosphate [N8888][DEHP].This IL was prepared in the similar procedure as above from [N8888]Br (5.46 g, 10.0 mmol) and HDEHP (3.22 g, 10.0mmol). [N8888][DEHP] was obtained as a viscous liquid (7.41 g, 9.4 mmol, yield: 94%). The water content of [N8888][DEHP] was0.3%.

Trioctylmethylammoniumbis(2-ethylhexyl)phosphate [N8881][DEHP].This IL was prepared in the similar procedure as above from [N8881]Cl (4.04 g, 10.0mmol) and HDEHP (3.22 g, 10.0mmol). [N8881][DEHP] was obtained as a colorless viscous liquid (6.35 g, 9.2 mmol, yield: 92%).

1-H-triethylammoniumdi(2-ethylhexyl)phosphate [N222H][DEHP].The product was formed by neutralization of equal molar ratio of triethylamine (1.15 g, 11.3 mmol) and Di(2-ethylhexyl)phosphoric acid (HDEHP, 3.64 g, 11.3 mmol) at room temperature for 2 hours. The mixture became more viscous upon stirring. The water content of [[N222H][DEHP] was 0.09%.

1-H-tributylammoniumdi(2-ethylhexyl)phosphate [N444H][DEHP]. The product was formed by neutralization of equal molar ratio of tributylamine (1.92 g, 10.4 mmol) and Di(2-ethylhexyl)phosphoric acid (HDEHP, 3.34 g, 10.4 mmol) at room temperature for 2 hours. The mixture became more viscous upon stirring. The water content of [[N444H][DEHP] was 0.12%.

1-H-trihexylammoniumdi(2-ethylhexyl)phosphate [N666H][DEHP]. The product was formed by neutralization of equal molar ratio of trihexylamine (2.27 g, 8.44 mmo)} and Di(2-ethylhexyl)phosphoric acid (HDEHP, 2.70 g, 8.44 mmol) at room temperature for 2 hours. The mixture became more viscous upon stirring. The water content of [[N666H][DEHP] was 0.08%.

1-H-trioctylammoniumdi(2-ethylhexyl)phosphate [N888H][DEHP]. The product was formed by neutralization of equal molar ratio of trioctylamine (2.37 g, 6.69 mmol) and Di(2-ethylhexyl)phosphoric acid (HDEHP, 2.16 g, 6.69 mmol) at room temperature for 2 hours. The mixture became more viscous upon stirring. The water content of [[N888H][DEHP] was 0.10%.