10.1081/SIM-120035948
This research investigates the synthesis and characterization of thiosemicarbazone-S-alkyl ester ligands derived from 2/3-formylpyridine and their complexes with Zn(II) and Pd(II) ions. The study aims to explore the structural properties and coordination behavior of these ligands with metal ions, given the biological significance of thiosemicarbazones and their metal complexes. Key chemicals used include thiosemicarbazide, methyl iodide, ethyl iodide, 2-formylpyridine, ZnCl?, and Li?[PdCl?]. The ligands and their metal complexes were characterized using elemental analyses, IR and 1H NMR spectroscopy. The findings reveal that the thiosemicarbazone-S-alkyl esters can act as mono-, bi-, or tridentate ligands depending on the alkyl group and metal ion, with notable differences in coordination behavior between Zn(II) and Pd(II) complexes. The study concludes that the coordination properties of these ligands are influenced by the position of the pyridine nitrogen and the steric hindrance of the alkyl group, providing insights into the design of metal complexes with potential biological applications.
10.1039/b008932j
The study focuses on the synthesis and characterization of metal complexes containing the asymmetric and potentially tridentate Schiff base ligand 1-[(4-methylphenyl)sulfonamido]-2-[(2-pyridylmethylene)amino]benzene, denoted as [L3]~. The researchers used various metals including manganese (Mn), cobalt (Co), copper (Cu), and zinc (Zn) to form complexes with this ligand. The purpose of these chemicals was to investigate the coordination chemistry of the Schiff base with different metal ions, exploring their structural variety and stereochemical models in coordination chemistry. The study involved the use of 2-pyridinecarboxaldehyde and N-tosyl-1,2-diaminobenzene to interact and form the Schiff base, and p-toluenesulfonic acid was added to facilitate the formation of M(II) complexes containing the ligand L1. The complexes were characterized using various analytical techniques such as elemental analyses, magnetic measurements, IR, mass spectrometry, and 1H NMR spectroscopy for structural elucidation. The study aimed to understand the behavior of the ligand in solution, its stability, and the geometric preferences of the metal complexes formed.
10.1021/jo00298a049
The research focuses on the synthesis and investigation of the reactivity of two phenanthroline-linked dihydronicotinamides, compounds 3 and 6, which serve as models for the NADH-alcohol dehydrogenase coenzyme-enzyme complex. The purpose of this study was to examine whether the metal ion in these models could mimic the function of catalytic zinc in alcohol dehydrogenase, specifically in binding the substrate near the dihydronicotinamide group, orienting the groups for hydride transfer, and activating the carbonyl group for reduction. The researchers concluded that the metal ion in these models, particularly when Zn2+ is present, could effectively mimic the catalytic function of zinc in the enzyme complex, with hydride transfer occurring within a ternary complex. Key chemicals used in the process include 1,4-dihydro-l-(l,l0-phenanthrolin-2-ylmethyl)-3-pyridinecarboxamide (3), 1,4-dihydro-N-(l,l0-phenanthrolin-2-ylmethyl)-l-(phenylmethyl)-3-pyridinecarboxamide (6), 2,4,6-trinitrobenzene sulfonate (TNBS), methylene blue (MB+), and 2-pyridinecarboxaldehyde (PyCHO), along with various metal ions (M2+ = Zn2+, Co2+, Ni2+, Mg2+, and Cd2+).
10.1139/v02-099
The research focuses on the synthesis and characterization of new hybrid inorganic-organic polymers containing cyclophosphazenes as pendant groups. The purpose of this study was to create multi-functional cyclophosphazene monomers that can be used to build polymeric ligand systems capable of binding to transition metal ions, which are of interest due to their potential applications in organic synthesis as solid-phase inert supports or as reagents and catalysts. The researchers successfully synthesized and converted cyclophosphazene ligands containing hydrazone linkages into soluble and thermally stable polymeric systems, retaining the ligand framework as pendant groups. Key chemicals used in the process include N-methylhydrazine, o-hydroxybenzaldehyde, pyridine-2-carboxaldehyde, and various cyclophosphazene derivatives.
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