Mixed ligand N₄O₂ type metal(II) complexes as metallointercalators: Preliminary investigation of DNA-binding/cleavage and antimicrobial

Abstract

The NMR spectrum is exploiting to determine the identity of prepared ligand and its diamagnetic metal complexes. Ligand and Zn(II) complex were recorded in DMSO-d 6 , using tetramethylsilane (TMS) as internal standard. The 1 H NMR spectrum of ligand shows a singlet peak at 9.71 ppm (1H, CH=N), multiplet in the range 6.60-7.90 ppm for the aromatic ring protons and a multiplet peak at 2.80-3.40 ppm for (12H, N-CH 3 ) protons. The proton 1 H NMR spectrum of Zn complex shows (Fig. S2.) a singlet peak at 9.67 ppm (1H, CH=N), multiplet in peaks at 6.60-7.90 ppm for the aromatic ring protons and a multiplet peak at 2.80-3.40 ppm for (6H, N-CH 3 ) protons. From the above observation, it is inferred that the azomethine group (CH=N) is involved in metal co-ordination. Powder XRDX-ray powder diffraction has been obtained for further confirmation, regarding the structure of the metal complexes. They are complicated to isolate single crystal suitable for a single crystal X-ray crystallography; it might be due to powder or polycrystalline nature of the complexes. However, the structural information on the majority of inorganic metal complexes is not suitable, because the materials have been polycrystalline or powder in nature. Generally it is hard to develop good quality single crystals of these inorganic complexes. In this metal complex, powder X-ray diffraction studies may be useful. The X-ray diffraction of metal complex is given in Fig. S3. which exhibits reflecting peaks of 2θ scattering angles at 13.