Three cadmium(II) complexes of N-(2-aminoethyl)-1, 2-ethanediamine (DETA) (1), N-(3-aminopropyl)-1, 3-propanediamine (DPTA) (2) and N,N'-(ethane-1,2-diyl)bis(propane-1,3-diamine) (DPETA) (3) have been synthesized and characterized by single crystal X-ray crystallography, UV–visible spectroscopy, IR and conductivity measurements. Complexes 1 and 3 show octahedral geometry while complex 2 show five coordinated square pyramidal geometry. Two molecules of DETA ligand are coordinated to the Cd(II) ion in complex 1. But one molecule each of DPTA and DPETA ligands and two bromide ions are coordinated to the Cd(II) ions to form square pyramidal (2) and octahedral structure (3). DFT results show that complex 3 is the most favoured complex thermodynamically while complex 1 is the least. The complexes exhibit good photocatalytic activity with reference to the intensity of organic dye methylene blue. The complexes were investigated for DNA interaction by absorption and fluorescence spectroscopy suggesting both hypochromism (internal contact or intercalative interaction) and hyperchromism (external contact or electrostatic binding). The cadmium (II) complexes show growth inhibitory activity against four pathogenic bacteria, two gram +ve, viz., Staphyloccus aureus, Bacillus subtilis and two gram –ve, viz., Escherichia coli, Salmonella typhi. Albumin denaturation assay and Heat Induced Haemolysis were studied for the complexes for anti-inflammatory activity.