Spectroscopic, computational, anti-bacterial studies of bivalent metal complexes of N-picolyl-amine dithiocarbamate

This study reports the synthesis of seven picolylamine dithiocarbamate complexes of M(II) {M = CoII ( 1 ), NiII ( 2 ), CuII ( 3 ), PdII ( 4 ), ZnII ( 5 ), CdII ( 6 ) and HgII ( 7 )}. CHN analysis, conductivity measurements, mag-netic susceptibility measurement, FT-IR, 1 H and 13C-NMR, SEM, and XRD were used to investigate the structural geometries of the complexes. The dithiocarbamate ligand coordinates to the M(II) ion in a bidentate mode through sulfur atoms forming a square planar or tetrahedral geometry. Moreover, the surface structural analysis revealed nano-pattern properties. For instance, complexes of Cd(II) and Hg(II) showed a nano-flower pattern, averaging 2-5 mu m. Furthermore, the obtained complexes exhibited bi-ological activity properties. The results showed that the new metal (II) compounds possessed remark-able antibacterial inhibition activity against both Gram-positive and Gram-negative bacteria. Additionally, the complexes [Ni(PA-dtc)2], [Cu(PA-dtc)2], and [Pd(PA-dtc)2] were theoretically studied and their quan-tum parameters were evaluated using Gaussian 09 program at B3LYP/SDD level of theory. The optimized structures of all of the three complexes showed square planar geometry. The calculated bond lengths showed close values, specifically for CSS and C -N group, which suggests a partially double bond charac-ter. Other quantum parameters have evaluated and showed similar properties such as the total energy, HOMO-LUMO energy gap, Affinity, Hardness, and dipole moment.(c) 2022 Elsevier B.V. All rights reserved.

Automated summary

This study synthesized seven picolylamine dithiocarbamate complexes of M(II) ions (CoII, NiII, CuII, PdII, ZnII, CdII, and HgII) and investigated their structural geometries and properties. The complexes showed a square planar or tetrahedral geometry formed by the coordination of the dithiocarbamate ligand through sulfur atoms. Surface structural analysis revealed nano-pattern properties, such as a nano-flower pattern in Cd(II) and Hg(II) complexes. The complexes exhibited remarkable antibacterial activity against both Gram-positive and Gram-negative bacteria.