Synthesis, Structural Characterization and Antimicrobial Activity of a Novel Cobalt(II) Complex Based on 3-Methyl-1-Phenyl-4-(2-Thienoyl)-Pyrazol-5-One

New cobalt(II) complex, [Co(O2C15H11N2S)2(OH2)2]∙2H2O (1∙2H2O), has been synthesized upon reaction of cobalt chloride hexahydrate (Co(Cl)2∙6H2O) with 3-methyl-1-Phenyl-4-(2-thienoyl)-pyrazol-5-one (referred as HL) in ethanol at room temperature. Single crystal X-ray diffraction (XRD), spectroscopic methods, and microelemental analyses were used to characterize 1∙2H2O. Compound 1∙2H2O crystallizes the orthorhombic system a Pbca space group atom being pseudo-octahedral coordinated. The broth microdilution technique was screen free ligand (HL) complex (1∙2H2O) for antimicrobial activities. HL low activity (MIC > 100 μg/mL) on all microorganisms, whereas compound displayed moderate (10 ∙2H2O exhibited bactericidal fungicidal respectively bacteria yeasts tested. These findings reveal that enhanced coordination Co(II) ion against microorganisms (bacteria fungus).