**2.1 Synthesis of 1-(2-aminoethyl)-3-ethylimidazolium tetrafluoroborate [2-aeeim]BF4 (1a)**

The FIL was synthesized by following a literature procedure [25]. [2-aeeim]BF4 was obtained as yellow oil; (98 mg, 70%); <sup>1</sup> H NMR (400 MHz, D2O, TMS): *δ* = 1 H NMR (400 MHz, D2O): δ = 3.63 (m, 2H, NH2▬CH2), 4.16 (s, 3H, CH3), 4.49 (t, 1H, N▬CH2), 4.56 (t, 1H, N▬CH2), 7.40 (s, 1H, NCH), 7.50 (s, 1H, NCH), 8.61 (s, 2H, NH2), 8.87 (s, 1H, N(H)CN); IR (KBr): ʋ = 3447, 3086, 2896, 1626, 1452, 1084. ESI-MS (*m/z*) calc for [C7H14N3] + : 140, found: 140 [M-BF4] + . Anal. calcd. for C7H14F4N3B: C 37.04, H 6.22, N 18.51, found: C 36.99, H 6.14, N 18.43.
