Spectral and Thermal Characterization and Antimicrobial Effect of 3-(5-H/Me/Cl/NO2-1H-benzimidazol-2-yl)-benzene-1,2-diols and Some Transition Metal Complexes

3-(5-H/Me/Cl/NO2-1H-benzimidazol-2-yl)-benzene-1,2-diols (HLX; X = 1-4) ligands and HL3 complexes with Fe(NO3)(3), Cu(NO3)(2), Co(NO3)(2), Zn(NO3)(2) have been synthesized and characterized. The structural representations of the compounds are proposed on the basis of elemental analysis, molar conductivity, TGA, mass, FT-IR, H-1- and C-13-NMR spectrometry. All of the complexes are 1:1 electrolyte and have 1:1 M:L ratio except that of Cu(II). All of the complexes present fluorescence, the Co(II) complex showing the highest fluorescence intensity and the highest emission wavelength in comparison to the other complexes. Antibacterial activities of the ligands and the complexes formed by the HL3 ligand were evaluated using the disk diffusion method against six bacteria and Candida albicans. HL1, HL2, HL3 and [Cu(HL3)(L-3)(H2O)(2)](NO3)center dot H2O show considerable antimicrobial activity toward S. epidermidis and C. albicans.