No abstract

A novel hydrazone ligand (o-H2BMP) N-(benzo­[d]­thiazol-2-yl)-3-oxo-3-(2-(1-(pyridin-2-yl)­ethylidene)­hydrazinyl)­propanamide alongside its Cu­(II), Cd­(II), and VO­(II) complexes were prepared and structurally characterized via various spectroscopic analyses (Fourier transform infrared spectroscopy, UV–visible spectroscopy, 1H/13C NMR spectroscopy, liquid chromatography coupled to mass spectrometry, and electron paramagnetic resonance spectroscopy) as well as by elemental analysis, thermal gravimetry analysis/differential thermal analysis, and magnetic moment measurements. Powder X-ray diffraction analysis was also performed for the free ligand and its metal complexes to determine the crystallographic structures and atomic spacing. It also provided information on unit cell dimensions and the average crystallite size. Furthermore, geometric optimization and computational studies were carried out by applying Gaussian (09) software based on density-functional theory coupled with the B3LYP functional and LANL2DZ/6-31+G­(d,p) mixed basis set to evaluate some distinct features such as molecular electrostatic potential, E HOMO, and E LUMO. Moreover, electrochemical measurements were performed for Cu­(II) in the absence/presence of the chelating agent to predict the effect of complexation interaction in the solution state study. As part of the biological examination, antioxidant and antimicrobial assays were conducted for each compound individually, in addition to cytotoxicity evaluations via MTT assays for all isolated complexes compared to the corresponding metal salts. The MOE (molecular operating environment) approach was also applied to model the interface between the isolated compounds and proteins that were expressed in breast cancer at the atomic level.

The association and thermodynamic association parameters for CdBr 2 were determined by the conductometric method in pure water and in a mixture of water−ethanol (0.30 mass fraction of ethanol) at different temperatures. The values of ion pair association was also calculated and found that CdBr 2 in ceftazidime drug has greater values compared to that in the absence of ceftazidime. Also, the complex formation constants and thermodynamic parameters for complex formation between CdBr 2 with ceftazidime as a ligand were also determined by the conductometric method. From the interaction of CdBr 2 with ceftazidime, two stoichiometric complexes were obtained 1:1 and 1:2. The complex K f and ΔG f are greater in the case of 1:1 than that of 1:2 (CdBr 2 / ceftazidime) complexes in 0% ethanol and in 30% ethanol solvents indicating easier complex formation. The formation constants decreased with increased temperature. The negative values of ΔG f for complexation indicate the spontaneity of the complex formation process and that the spontaneity increased with temperature. The negative values of ΔH f show the exothermic nature of the complexation and indicate that the complexation processes are more favored at low temperatures. The ΔS f values for the complexation are positive, confirming that the complex formation is entropically favorable. Significance of the study is to give a lot of data which can be easily obtained for following the very toxic heavy metal cadmium ions.