A new series of novel homoleptic and heteroleptic Cd(II) complexes using cyclopropanecarboxylic acid (HL1) and cyclopentanecarboxylic acid (HL2) as main ligands and N-donor species like 2,2′-bipyridine (bpy), 1,10-phenanthroline (phen), and 2,9-dimethyl-1,10-phenanthroline (Me2phen) as co-ligands were prepared and characterized by FT-IR, multinuclear (1H and 13C) NMR, and UV–Visible spectroscopies. Furthermore, the crystal structure of the Cd(II) complex coordinated by cyclopentanecarboxylic acid (HL2) and 1,10-phenanthroline (phen) was explored by single crystal X-ray diffraction (SC-XRD) analysis. The crystal structure was binuclear, in which the coordination geometry around each cadmium center was distorted pentagonal bipyramidal coordination geometry. Various intermolecular interactions were accountable for stabilizing the supramolecular associations, which were seen by Hirshfeld surface analysis in terms of interatomic contacts. The spectroanalytical data of the synthesized complexes confirm the absence of the –OH band in the spectra of complexes as compared to the spectra of the free ligands, which favour the formation of complexes. The nature of complex-DNA interaction and the effect of the coordination of heteroligands on the binding strength of complexes were probed through UV–Visible spectroscopy and cyclic voltammetry. The obtained data confirm that the interaction of DNA with the complexes is dual: intercalation as well as groove binding. The DNA binding constants (Kb) and Gibb’s free energy changes (ΔG) were also determined for these complexes. This study aims to project effective drugs with the least harmful effects that could be useful for mankind against dreadful diseases.
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