The Complex of Cr(III) with Ligand of 2,6-Bis(pyrazol-3-yl)pyridine and Anionic Trifluoromethanesulfonate: Synthesis, Characterization and Antibacterial Activity

Abstract

The complex containing chromium(III), 2,6-bis(pyrazol-3-yl)pyridine (3-bpp), and CF3SO3– (trifluoromethanesulfonate (triflate)) has been prepared and characterized. The conductance, metal content, and thermogravimetric and differential thermal analysis (TGA-DTA) analysis suggest the complex to be [Cr(3-bpp)2](CF3SO3)3.2H2O. The paramagnetic moment corresponds to the three unpaired electrons being consistent with the electronic configuration of chromium(III). The electronic spectral bands are not well resolved attributed to the spin-allowed transitions of quartet ground state to quartet excited states. The IR spectral data signify the mode of vibrations typical for 3-bpp as well as the triflate. While the images of scanning electron microscope-energy dispersive X-ray (SEM) photographs confirm the crystalline particle size and the energy dispersive X-ray (EDX) signifies the existence of all elemental content. The analysis of powder-X-ray diffraction (powder-XRD) following the Rietica program of Le Bail suggests being a structurally orthorhombic crystal system, and Pbca space group, with Z = 16, Rp = 4.30, Rwp = 5.14, Rexp = 12.17, R-FBragg = 0.04, and goodness of fitting (GOF) = 0.1783. The complex shows a weak inhibition of bacterial activity against S. aureus and E. coli.