On the coordination behavior of the hmta toward zinc and cadmium cations in presence of sulfate(VI) and nitrate(V) anions

Design, Synthesis, and Characterization of Novel Coordination Compounds of Benzimidazole Derivatives with Cadmium

Four complexes of Cd(II) with benzimidazole derivatives were synthesized and named C1, C2, C3, and C4. All coordination compounds were characterized through elemental analysis (EA), flame atomic absorption spectrometry (FAAS), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis coupled with mass spectrometry) (TG-MS), a cytotoxicity assay (MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide)), and computational chemical analysis for absorption, distribution, metabolism, and excretion (ADME). All of the obtained results are compatible and are consistent with the respective structures of the obtained compounds and their properties. The various techniques used allowed the determination of the composition, proposed structure of the compounds, their thermal stability and thermal properties, and the method of coordination between the metal (II) ion and the ligand. The ADME technique was also used to estimate the physicochemical and biological properties. The antitumor activity of the compounds was determined with an MTT assay on the glioblastoma (T98G), neuroblastoma (SK-N-AS), and lung adenocarcinoma (A549) cell lines, as well as normal human skin fibroblasts (CCD-1059Sk). Compound C2 was found to have potential antitumor properties and to be effective in inhibiting the growth of neuroblastoma cells. The antimicrobial activity of Cd complexes, free ligands, and reference drugs was tested against six strains of Gram-positive bacteria, five strains of Gram-negative rods, and three strains of yeasts. Compound C3 significantly increased activity against Gram-positive bacteria in comparison to the ligand.

Copper(II) 2,2-Bis(Hydroxymethyl)Propionate Coordination Compounds with Hexamethylenetetramine: From Mononuclear Complex to One-Dimensional Coordination Polymer

Three new copper coordination compounds derived from 2,2-bis(hydroxymethyl)propionic acid (dmpa) and hexamethylenetetramine (hmta) were obtained and their crystal structures were determined. The stoichiometry of the reagents applied in the syntheses reflects the metal to ligand molar ratio in the formed solid products. Due to the multiple coordination modes of the used ligands, wide structural diversity was achieved among synthesized compounds, i.e., mononuclear [Cu(dmp)₂(hmta)₂(H₂O)] (1), dinuclear [Cu₂(dmp)₄(hmta)₂] (2), and 1D coordination polymer [Cu₂(dmp)₄(hmta)]_n (3). Their supramolecular structures are governed by O—H•••O and O—H•••N hydrogen bonds. The compounds were characterized in terms of absorption (UV-Vis and IR) and thermal properties. The relationships between structural features and properties were discussed in detail. Owing to discrepancies in the coordination mode of a dmp ligand, bidentate chelating in 1, and bidentate bridging in 2 and 3, there is a noticeable change in the position of the bands corresponding to the stretching vibrations of the carboxylate group in the IR spectra. The differences in the structures of the compounds are also reflected in the nature and position of the UV-Vis absorption maxima, which are located at lower wavelengths for 1.