Carboxylate ligands are widely used in chemistry and pharmacy owing to their ability to form stable complexes with a large variety of metal ions. In that context, carboxylate complexes allow modulation of the pharmaceutical products. Herein, a series of six novel Zn(II) carboxylates: [Zn(L1)2] (1), [Zn(L1)2 (bipy)] (2), [Zn(L1)2 (phen)] (3), [Zn(L2)2] (4), [Zn(L2)2 (bipy)] (5) and [Zn(L2)2 (phen)] (6) (where L1 = 4-(2-methoxy-5-nitrophenylamino)-4-oxobutanoic acid), L2 = 4-(2-nitro-4-methoxyphenylamino)-4-oxobutanoic acid), phen = 1,10-phenanthroline and bipy = 2,2′-bipyridine) were synthesized in good yield and successfully characterized by 1H, 13C NMR, FT-IR and single-crystal X-ray crystallography. The spectroscopic data reveal that the absence of OH peak in the spectra of complexes confirm their formation. Single-crystal X-ray crystallographic data for complexes 1 and 5 show a distorted octahedral environment around the Zn atom. The results of both FT-IR and single-crystal X-ray crystallography confirm the bidentate nature of the carboxylate ligands. The DNA interaction study of the synthesized complexes was investigated using UV–visible spectroscopy and viscosity measurements suggesting an intercalative binding mode of interaction of the complexes with SS-DNA. The interaction between the synthesized complexes and CTAB was elaborately studied with a conductometric method. The conductivity method was used to find CMC, higher CMC values suggesting a stable complex-CTAB system. Results of in vitro antibacterial and antifungal activities indicate the biological potency of the synthesized compounds.