Bioinorganic Chemistry and Applications

Research Article

Preparation and Characterization of Di-, Tri-, and Tetranuclear Schiff Base Complexes Derived from Diamines and 3,4-Dihydroxybenzaldehyde

Table 3

1H NMR data of the three Schiff base ligands and the Cu(II) complex C11 in DMSO.
EDH4PDH4
Chemical shift
(ppm)		AssignmentsChemical shifts
(ppm)		Assignments
(8.8–9.9, 4H, b)Protons of OH(9.60–9.75, 4H, b)Protons of OH
(8.1, 2H, s)Protons of azomethine(8.7–7.9, 2H, b)Protons of azomethine
(6.7–7.4, 6H, m)Aromatic protons (6.5–7.9, 10H, b)Aromatic protons
(3.9, 4H, s)Protons of NCH2(3–3.5, 8H, b)Protons of H2O
(3–3.5, 2H, b)Protons of H2O (in DMSO)(2.5, 6H, s)Protons of DMSO
(2.5, 6H, s)Protons of DMSO  
MPDH4C11 complex
Chemical shifts
δ (ppm)		AssignmentsChemical shifts
(ppm)		Assignments
(8.5–8.68, 4H, b)Protons of OH(10.1–10.98, 2H, b)Protons of azomethine
(8.0–8.28, 2H, b)Protons of azomethine(6.7–7.5, 24H, b)Aromatic protons of benzene rings and bipyridyl
(6.9–7.6, 10, m)Aromatic protons (3.2, 6H, m)Protons of H2O
(3.0–3.6, 2H, m)Protons of H2O(2.4–2.8, 6H, m)Protons of DMSO
(2.5, 6H, s)Protons of DMSO(0.97–1.85, 6H, b)Protons of CH3
(1.5–1.7, 6H, m)Protons of CH3——