Table 3.
1H NMR spectral dataa of the ligands and their corresponding Me3Si(IV) complexes.
| Compounds | Chemical Shift (δ, ppm) |
|---|---|
| L1H | 11.28 (s, 1H, COOH), 4.30 (s, 2H, N–CH2–), 8.02 (s, 1H, NH), H-aromatic: 7.58 (d, J = 7.8, 1H), 7.28–7.48 (m, 2H,), and 7.80 (d, J = 7.7, 1H). |
| Me3SiL1 | 4.32 (s, 2H, N–CH2–), 8.03 (s, 1H, NH), H-aromatic: 7.72 (d, J = 7.6, 1H), 7.22–7.52 (m, 2H,), 7.98 (d, J = 7.3, 1H), and 1.32 (s, 9H, Si–CH3) |
| L2H | 11.25 (s, 1H, COOH), 4.72 (q, 1H, CH), 8.34 (s, 1H, sec. amide), 1.31 (d, J = 6.8, 3H, CH3), H-aromatic: 7.61 (d, J = 7.6, 1H), 7.21–7.41 (m, 2H,), and 7.82 (d, J = 7.4, 1H). |
| Me3SiL2 | 4.70 (q, 1H, CH), 8.36 (s, 1H, sec. amide), 1.28 (d, 3H, CH3), H-aromatic: 7.66 (d, J = 7.7, 1H), 7.20–7.46 (m, 2H,), 7.98 (d, J = 7.6, 1H), and 1.25 (s, 9H, Si–CH3) |
| L3H | 11.74 (s, 1H, COOH), 4.72 (d, J = 6.8, 1H, CH), 8.05 (s, 1H, sec. amide), 2.30 (m, 2H, CH2), 2.04 (d, J = 6.4, 3H, CH3), H-aromatic: 7.58 (d, J = 8.1, 1H), 7.18–7.38 (m, 2H,), and 7.72 (d, J = 7.6, 1H). |
| Me3SiL3 | 4.50 (d, 1H, CH), 8.01 (s, 1H, sec. amide), 2.22 (m, 2H, CH2), 2.06 (d, 3H, CH3), H-aromatic: 7.64 (d, J = 7.9, 1H), 7.16–7.46 (m, 2H,), 7.88 (d, J = 7.5, 1H), and 1.26 (s, 9H, Si–CH3) |
| L4H | 11.50 (s, 1H, COOH), 4.25 (t, 1H, N–CH–CH2–), 3.08 (d, J = 6.8, 2H, –CH2–Ph), 8.01 (s, 1H, NH), ), H-aromatic: 7.62 (d, J = 8.1, 1H), 7.20–7.45 (m, 2H,), and 7.80 (d, J = 7.8, 1H). |
| Me3SiL4 | 4.26 (t, 1H, N–CH–CH2–), 3.12 (d, J = 6.9, 2H, –CH2–Ph), 8.08 (s, 1H, NH), H-aromatic: 7.70 (d, J = 7.9, 1H), 7.20–7.45 (m, 2H,), 7.98 (d, J = 7.8, 1H), and 1.30 (s, 9H, Si–CH3) |
| L5H | 11.46 (s, 1H, COOH), 4.39 (d, J = 8.3, 1H, CH), 8.12 (s, 1H, sec. amide), 10.15 (s, 1H, indole), 3.02 (m, 2H, CH2), H-aromatic: 7.65 (d, J = 7.8, 1H), 7.15–7.30 (m, 2H,), and 7.84 (d, J = 7.6, 1H). |
| Me3SiL5 | 3.16 (d, 1H, CH), 8.07 (s, 1H, sec. amide), 10.18 (s, 1H, indole), 2.98 (m, 2H, CH2), H-aromatic: 7.64 (d, J = 7.7, 1H), 7.18–7.42 (m, 2H,), 8.01 (d, J = 7.6, 1H), and 1.25 (s, 9H, Si–CH3) |
| L6H | 12.55 (s, 1H, COOH), 4.61 (d, J = 7.2, 1H, CH), 8.10 (s, 1H, sec. amide), 12.92 (s, 1H, imidazole), 3.15 (m, 2H, CH2), H-aromatic: 7.60 (d, J = 7.9, 1H), 7.08–7.38 (m, 2H,), and 7.80 (d, J = 7.7, 1H). |
| Me3SiL6 | 3.98 (d, 1H, CH), 8.03 (s, 1H, sec. amide), 12.79 (s, 1H, imidazole), 3.10 (m, 2H, CH2), 7.62 (d, J = 7.8, 1H), 7.10–7.44 (m, 2H), 7.94 (d, J = 7.7, 1H), and 1.28 (s, 9H, Si–CH3) |
| L7H | 11.72 (s, 1H, COOH), 4.80 (d, J = 6.9, 1H, CH), 8.15 (s, 1H, sec. amide), 2.30 (m, 2H, CH2), 2.10 (d, J = 6.5, 3H, CH3), H-aromatic: 7.56 (d, J = 7.7, 1H), 6.95–7.36 (m, 2H,), and 7.76 (d, J = 7.8, 1H). |
| Me3SiL7 | 4.86 (d, J = 6.9, 1H, CH), 3.10 (m, 1H, CH), 8.10 (s, 1H, sec. amide), 2.25 (m, 2H, CH2), 2.02 (d, J = 6.3, 3H, CH3), H-aromatic: 7.66 (d, J = 7.7, 1H), 7.12–7.48 (m, 2H,), 7.95 (d, J = 7.9, 1H), and 1.20 (s, 9H, Si–CH3) |
| L8H | 12.28 (s, 1H, COOH), 4.45 (t, 1H, –CH–), 3.28 (d, J = 6.5, 2H, CH2), H-aromatic: 7.60 (d, J = 7.8, 1H), 7.12–7.38 (m, 2H,), and 7.82 (d, J = 7.7, 1H). |
| Me3SiL8 | 4.40 (t, 1H, –CH–), 3.25 (d, J = 6.6, H, CH2), H-aromatic: 7.65 (d, J = 7.8, 1H), 7.14–7.50 (m, 2H,), 7.92 (d, J = 7.8, 1H), and 1.27 (s, 9H, Si–CH3) |
aChemical shift (δ) in ppm: multiplicity is given as s: singlet, d: doublet, t: triplet, q: quartet, and m: complex pattern.