| Assignment | Proton chemical shift (ppm) | Assignment | Carbon chemical shift (ppm) | Experimental | Theory | Experimental | Theory |
| 1,3-Bis(2-hydroxyethyl) imidazolidinium bromide (LA) | s, 1H, NCHN | 9.06 | 9.06 | NCHN | 136.33 | 137.66 | d, 2H, HC=CH | 7.70 | 7.32 | HC=CH | 122.60 | 123.06 | t, 4H, N-CH2 | 3.93 | 4.01 | O-CH2 | 59.75 | 61.68 | t, 4H, O-CH2 | 3.82 | 3.87 | N-CH2 | 51.98 | 52.59 | s. 2H, OH | — | 1.73 | — | — | — |
| 3-(2-Ethoxy-2-oxoethly)-1-(3-aminopropyl)-1H-imidazol-3-ium bromide (LB) | s, 1H, NCHN | 7.79 | 7.73 | CO | 171.85 | 172.23 | d, 1H, HC=CH | 7.25 | 7.23 | NCHN | 136.78 | 137.10 | d, 1H, HC=CH | 7.02 | 7.00 | HC=CH | 125.13 | 124.74 | s, 2H, N-CH2 CO | 4.23 | 4.22 (2) | HC=CH | 120.73 | 121.34 | q, 2H, CH2-CH3 | 3.23 | 3.21 (3) | O-CH2-CH3 | 60.78 | 57.36 | t, 2H, N-CH2-C | 2.95 | 2.96 (3) | N-CH2 | 54.97 | 54.10 | t, 2H, NH2-CH2 | 2.55 | 2.54 (2) | N-CH2-CH2- | 44.97 | 38.64 | m, 2H, C-CH2-C | 2.20 | 2.18 (2) | NH2-CH2- | 36.84 | 36.61 | t, 3H, CH3 | 2.02 | 2.04 (3) | C-CH2-C | 28.72 | 31.52 | NH2 | — | 0.5 (3) | CH3 | 13.64 | 17.70 |
| 1,3-Bis(2-carboxyethyl)-4-methyl-1H-imidazol-3-ium bromide (LC) | s, 1H, NCHN | 8.84 | 8.83 | COOH | 173.03 | 170.3 (1) | s, 1H, HC=C-CH3 | 7.33 | 7.34 | NCHN | 133.30 | 132.96 | s, OH | — | 5.95 (2) | C-CH3 | 129.94 | 130.93 | t, 4H, N-CH2 | 3.64 | 3.62 (5) | C=C-CH3 | 116.01 | 119.67 | N-CH2 | 37.53 | 39.7 (9) | t, 4H, CH2-COOH | 2.91 | 3.10 (2) | CH2-COOH | 26.79 | 33.8 (5) | s, 3H, -CH3 | 2.38 | 2.37 | CH3 | 9.01 | 10.26 |
| 3-(2-Carboxyethyl)-1-(3-aminopropyl)-1H-imidazol-3-ium bromide (LD) | s, 1H, NCHN | 9.11 | 9.11 | COOH | 170.21 | 177.74 | d, 1H, HC=CH | 7.72 | 7.71 | NCHN | 137.16 | 137.47 | d, 1H, HC=CH | 7.65 | 7.63 | HC=CH | 123.94 | 124.97 | s, OH | — | 6.39 | HC=CH | 121.50 | 124.69 | t, 4H, N-CH2 | 4.45 | 4.47 (1) | N-CH2 | 60.01 | 60.29 | t, 2H, COOH-C | 3.33 | 3.34 | N-CH2 | 52.02 | 53.30 | t, 2H, NH2-CH2 | 3.05 | 3.03 | NH2-CH2 | 45.42 | 45.41 | m, 2H, C-CH2-C | 2.33 | 2.31 | C-CH2-C | 36.18 | 40.05 | NH2 | — | 0.7 (3) | COOH-CH2 | 27.76 | 34.43 |
|
|