Book comprises the synthesis of dimeric octahedral complexes of Co(II) and Zn(II) bridged by piperazine ring and their characterization. Synthesized complexes are evaluated for their antimicrobial activity using Zone of inhibition and MIC (Minimum Inhibitory Concentration: Broth dilution method), Nuclease activity was studied by using Viscosity measurement supported by Absorption Titration. DNA cleavage study was done on 1% agarose gel electrophoresis stained with 1mg/ml of Ethidium Bromide followed by analysis by photo quantization on AlphaDigiDocTM RT. Version V.4.1.0 PC-Image software.