The N(4)-methylthiosemicarbazone derivatives H₂DDMT (1) and H₂DMMT (2) have been prepared from the reaction of 4-methylthiosemicarbazide with 2,3-dihydroxybenzaldehyde and 2-hydroxy-5-methylbenzaldehyde, respectively. Six new organotin(IV) complexes, [MeSnCl(DDMT)] (3), [BuSnCl(DDMT)] (4), [PhSnCl(DDMT)] (5), [MeSnCl(DMMT)] (6), [BuSnCl(DMMT)] (7), and [PhSnCl(DMMT)] (8) have been synthesized by direct reaction of corresponding organotin(IV) chloride(s) with these ligands. The ligands and their compounds have been characterized by elemental analysis, molar conductivity, UV–Vis, FT-IR, and NMR (¹H, ¹³C, and ¹¹⁹Sn) spectroscopy. The molecular structures of 1 and 2 were determined by X-ray crystallography. Spectroscopic data suggested that the ligands were coordinated to tin(IV) as dinegative tridentate via phenoxide-O, azomethine-N, and thiolate-S atoms. The crystal structures revealed that the ligands exist in thione form in the solid state. In vitro cytotoxicity assays were carried out for all the compounds against MCF-7 cancer cell line. The results have shown that different organotin(IV) groups showed characteristic differences in their biological activity. Graphical abstract Six new organotin(IV) complexes with 2,3-dihydroxybenzaldehyde-N(4)-methylthiosemicarbazone H₂DDMT (1) and 2-hydroxy-5-methylbenzaldehyde-N(4)-methylthiosemicarbazone H₂DMMT (2), [MeSnCl(DDMT)] (3), [BuSnCl(DDMT)] (4), [PhSnCl(DDMT)] (5), [[MeSnCl(DMMT)] (6), [BuSnCl(DMMT)] (7), and [PhSnCl(DMMT)] (8) have been synthesized. The ligands are coordinated to tin(IV) through the phenoxide-O, azomethine-N, and thiolate-S as a dinegative tridentate chelating agent; the coordination number of tin is five. In vitro cytotoxicity assays against MCF-7 cancer cell line showed that 3–8 possess activity.

The reaction of pyruvic acid phenylhydrazone [HPAPD, (1)] with organotin(IV) chloride(s) leads to the formation of five new organotin(IV) complexes: [MeSnCl₂(PAPD)] (2), [BuSnCl₂(PAPD)] (3), [PhSnCl₂(PAPD)] (4), [Me₂SnCl(PAPD)] (5), and [Ph₂SnCl(PAPD)] (6). The ligand [HPAPD, (1)] and its organotin(IV) complexes (2–6) have been characterized by CHN analyses, molar conductivity, UV-Vis, FT-IR, ¹H, ¹³C, and ¹¹⁹Sn NMR spectral studies. Spectroscopic data suggested that HPAPD is coordinated to tin(IV) through the carboxylato-O and azomethine-N as a mononegative bidentate chelating agent; the coordination number of tin is five. Compound 1 and its organotin(IV) complexes (2–6) were assayed for in vitro antibacterial activity against Staphylococcus aureus, Bacillus subtilis, Enterobacter aerogenes, Escherichia coli, and Salmonella typhi. The screening results show that 2–6 have better antibacterial activity than 1 and that 6 exhibits significantly better activity than 2–5.

Magnetic chitosan/cellulose nanofiber-Fe(III) [M-Ch/CNF-Fe(III)] composites were isolated for the elimination of Cr(VI), Cu(II), and Pb(II) from aqueous solution. Various analytical methods, such as field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction analysis (XRD), and thermogravimetric analysis (TGA) were employed to determine the morphological, physicochemical, and thermal properties of the isolated M-Ch/CNF-Fe(III) composites. It was found that the M-Ch/CNF-Fe(III) composites were porous materials, and they have the potential to be implemented as an adsorbent for heavy metals removal. The adsorption efficiency of M-Ch/CNF-Fe(III) composites was determined for Cr(VI), Cu(II), and Pb(II) elimination with changing pH (pH 1.0–8.0), adsorbent doses (0.05–1.0 g), time (15–90 min), and temperature (28–80 °C). In addition, isothermal and kinetics studies were conducted to assess the adsorption behavior and mass transfer phenomena of M-Ch/CNF-Fe(III) composites as an adsorbent for Cr(VI), Cu(II) and Pb(II) elimination from aqueous solution. The outcomes of the present study reveal that the M-Ch/CNF-Fe(III) composites could be utilized as an adsorbent for the Cr(VI), Cu(II), and Pb(II) elimination from industrial effluents.