Molecules 2019, 24, 2635
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Figure 6. The structure of the receptor 2 with the designations of hydrogen and carbon atoms.
Tetraamide
3
: White solid. Yield 32% (R), αrDt = +73.5 (c = 0.1, CH2Cl2); yield 35% (S), αrDt
9.01 (bs, 2H), 8.34 (d, J = 7.7 Hz, 2H), 8.09 (d,
=
−
73.5 (c = 0.1,
CH2Cl2), m.p. 143–144 ◦C; 1H-NMR (400 MHz, CDCl3)
δ
J = 8.9 Hz, 2H), 7.97 (t, J = 7.2 Hz, 3H), 7.55–7.29 (m, 6H), 7.21 (d, J = 8.4 Hz, 2H), 5.91 (bs, 2H), 4.55 (s,
4H), 3.83–3.63 (m, 2H), 3.40–3.23 (m, 2H), 3.22–2.91 (m, 4H), 1.59–1.27 (m, 9H); 13C-NMR (101 MHz,
CDCl3)
δ 168.5, 163.8, 152.4, 149.0, 138.4, 133.5, 130.6, 129.8, 128.2, 127.5, 125.2, 124.9, 124.6, 119.7, 114.3,
68.7, 39.6, 38.1, 27.9, 24.9; HRMS (m/z): cacld. for C39H39N5O6Na [MNa+]: 696.2798, found 696.2799.
Octaamide 95.1 (c = 0.1,
: White solid. Yield 17% (R), αrDt = +95.1 (c = 0.1, CH2Cl2); yield 5% (S), αrDt
CH2Cl2); m.p. 186–188 ◦C; 1H-NMR (400 MHz, CDCl3)
9.08 (bs, 4H), 8.32 (d, J = 7.7 Hz, 4H), 8.03 (t,
8
=
−
δ
J = 7.7 Hz, 2H), 7.93–7.77 (m, 8H), 7.43 (t, J = 7.3 Hz, 4H), 7.36–7.24 (m, 8H), 7.09 (d, J = 8.4 Hz, 4H),
6.87 (bs, 4H), 4.46 (ABq, J = 38.2, 15.3 Hz, 8H), 3.74–3.59 (m, 4H), 3.53–3.40 (m, 4H), 3.35–3.12 (m, 8H);
13C-NMR (101 MHz, CDCl3)
δ 170.6, 163.9, 154.0, 148.3, 138.9, 133.6, 130.5, 130.4, 128.1, 127.2, 125.2,
125.0, 124.4, 121.6, 117.9, 71.4, 40.8, 38.7; HRMS (m/z): cacld. for C70H62N10O12Na [MNa+]: 1257.4446,
found 1257.4442.
Octaamide
9
: White solid. Yield 10% (R), αrDt = +96.3 (c = 0.1, CH2Cl2); yield 12% (S), αrDt
9.02 (t, J = 6.4 Hz, 4H), 8.25 (d, J = 7.8 Hz, 4H),
= 96.3 (c = 0.1,
−
CH2Cl2); m.p. 175–177 ◦C; 1H-NMR (400 MHz, CDCl3)
δ
8.07–7.88 (m, 10H), 7.48–7.21 (m, 16H), 5.68 (t, J = 6.2 Hz, 4H), 4.40 (qAB, J = 14.6 Hz, 8H), 3.34–3.19 (m,
4H), 3.15–2.95 (m, 8H), 2.86–2.71 (m, 4H), 1.42–1.27 (m, 4H), 1.25–1.08 (m, 4H); 13C-NMR (101 MHz,
CDCl3)
δ 168.5, 163.6, 152.5, 148.7, 138.8, 133.4, 130.5, 129.9, 128.4, 127.5, 125.0, 124.9, 124.4, 119.8, 114.9,
68.5, 35.9, 35.5, 29.0; HRMS (m/z): cacld. for C74H70N10O12Na [MNa+]: 1313.5072, found 1313.5098.
Octaamide 10: White solid. Yield 11% (R), αrDt = +96.6 (c = 0.1, CH2Cl2); 10% (S), αrDt
96.6 (c = 0.1,
CH2Cl2); m.p. 159–160 ◦C; 1H-NMR (400 MHz, CDCl3)
8.92 (bs, 4H), 8.45 (d, J = 7.7 Hz, 4H), 8.11 (t,
=
−
δ
J = 7.7 Hz, 2H), 8.02 (d, J = 8.9 Hz, 4H), 7.91 (d, J = 8.1 Hz, 4H), 7.42 (t, J = 7.3 Hz, 4H), 7.35–7.22 (m,
9H), 7.14 (d, J = 8.4 Hz, 4H), 5.85 (bs, 4H), 4.51 (d, J = 14.9 Hz, 4H), 4.31 (d, J = 14.9 Hz, 4H), 3.52–3.35
(m, 4H), 3.31–3.12 (m, 4H), 3.07–2.73 (m, 9H), 1.35–1.08 (m, 16H); 13C-NMR (101 MHz, CDCl3)
δ 168.1,
163. 9, 152.0, 149.0, 138.8, 133.4, 1306, 129.7, 128.2, 127.5, 125.0, 124.8, 119.4, 114.0, 68.1, 39.2, 38.3, 26.7,
26.4; HRMS (m/z cacld. for C78H78N10O12Na [MNa+]: 1369.5698, found 1369.5720.
4.3. Titration Experiments
Tetrabutylammonium (TBA) salts of examinate anions were prepared before every titration
experiments, namely commercially available carboxylic acid (from Sigma Aldrich or TCI Europe) was
dissolved in 0.5 mL of dry methanol and one equivalent of TBAOH (solution in methanol, c = 1.21 M)
was added. Prior to the experiment, the salts were pre-dried overnight under high vacuum at 60 ◦C.
To obtain the appropriate water concentration distilled water was added to the commercially available
DMSO-d6 or acetone-d6 of 99.9% isotopic purity. All titration experiments was performed on Bruker
(400 MHz) at 298K.