Transition Metal(II) Complexes with Cefotaxime-Derived Schiff Base: Synthesis, Characterization, and Antimicrobial Studies

Table 1

¹H and ¹³C NMR spectral data of the ligand and Zn(II) complex.

Compound	^1H NMR δ (ppm)	^13C NMR δ (ppm)
Schiff base (L); C23H20S2O8N5Na	2.10 (3H, s, COOCH3); 4.72, 4.90 (2H, AB, 𝐽=12.2 Hz, C3–CH2); 3.40, 3.67 (2H, AB, 𝐽=17.2 Hz, C2–H2); 5.22 (1H, d, 𝐽=4.6 Hz, C5–H β-lactam); 5.79 (1H, d, 𝐽=4.6 Hz, C7–H β-lactam); 9.53 (1H, s, –NH–CO); 3.99 (3H, s, OCH3); 6.73 (1H, s, thiazolyl–C16–H); 8.7 (1H, s, –HC=N); 10.2 (1H, s, –OH); 7.5 (4H, m, –phenyl)	163.0; 143.4; 109.9 (C17; C15; C16–thiazole ring); 168.39 (C13); 169.3; (C12); 58.12; 65.4; 171.4 (C5; C7; C6  β-lactam); 139.5; 112.2; 26.2 (C4; C3; C2); 58.3 (C9); 163.9 (C10); 21.6 (C11); 165.0 (C8); 62.7 (C14); 163.62 (–HC=N); 157.82 (C20 phenyl); 132.24; 130.46; 121.25; 117.43; 112.87 (C19, C21, C22, C23, C24 phenyl)
ZnL2(H2O)2; ZnC46H42S4O18N10Na2	2.10 (3H, s, COOCH3); 4.72, 4.90 (2H, AB, 𝐽=12.2 Hz, C3–CH2); 3.40, 3.67 (2H, AB, 𝐽=17.2 Hz, C2–H2); 5.22 (1H, d, 𝐽=4.6 Hz, C5–H β-lactam); 5.79 (1H, d, 𝐽=4.6 Hz, C7–H β-lactam); 9.53 (1H, s, –NH–CO); 3.99 (3H, s, OCH3); 6.73 (1H, s, thiazolyl–C16–H); 8.96 (1H, s, –HC=N); 7.5 (4H, m, –phenyl)	163.0; 143.4; 109.9 (C17; C15; C16 thiazole ring); 168.39 (C13); 169.3; (C12); 58.12; 65.4; 171.4 (C5; C7; C6  β-lactam); 139.5; 112.2; 26.2 (C4; C3; C2); 58.3 (C9); 163.9 (C10); 21.6 (C11); 165.0 (C8); 62.7 (C14); 168.16 (–HC=N); 157.82 (C20 phenyl); 132.24; 130.46; 121.25; 117.43; 112.87 (C19, C21, C22, C23, C24 phenyl)