Research Article
Green Synthesis, Characterization and Biological Evaluation of Divalent Transition Metal Complexes of Substituted Aminopyrimidine Novel Schiff Base Ligand
Dhondiram Tukaram Sakhare*
Issue:
Volume 13, Issue 1, February 2025
Pages:
1-10
Received:
4 November 2024
Accepted:
22 December 2024
Published:
7 January 2025
DOI:
10.11648/j.sjc.20251301.11
Downloads:
Views:
Abstract: The aminopyrimidines so obtained were converted into Schiff bases by treating with different substituted aldehydes, The study of novel heterocyclic Schiff base ligands 3-{[(4,6-dihydroxy pyrimidin-2-yl)Imino]methyl}Napthalen-2-ol or 2-(((2-hydroxynaphthalen-1-yl)methylene)amino)pyrimidine-4,6-diol derived from 2-amino-4, 6-dihydroxypyrimidine and 2-hydroxy-1-naphthaldehyde (L) were synthesized. These ligands have been used in the synthesis of Cr(II) complexes. The ligand coordinates to the metal ions in the ratio 2L: 1M, through the azomethine N and napthol O atoms, resulting in N2O2 chromophores around the central metal atom. The structures of synthesized compounds were confirmed by physical parameters and spectral studies. The synthesized compounds were characterized using FT-IR, 1H-NMR, UV-Vis techniques for the ligands, Thin layer chromatography (TLC) for all reactions, and molar conductivity and magnetic susceptibility measurements for the corresponding reactions. The general formula of the complexes is [Cr(L)2(H2O)2]. The complexes are paramagnetic in nature. Molar conductivity measurements showed that all complexes in (DMSO) are non electrolytes. Octahedral geometry of all complexes. The ligands are bidentate (L) due to the phenolic (OH) nitrogen and the azomethine nitrogen. The ligands and their complexes were examined for antifungal and antibacterial activity against Aspergillus niger, Penicillium chrysogenum, Fusarium moneriforme, and Aspergillus flavus, as well as Escherichia coli, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis. The results showed that the complexes have excellent antifungal and antibacterial effects.
Abstract: The aminopyrimidines so obtained were converted into Schiff bases by treating with different substituted aldehydes, The study of novel heterocyclic Schiff base ligands 3-{[(4,6-dihydroxy pyrimidin-2-yl)Imino]methyl}Napthalen-2-ol or 2-(((2-hydroxynaphthalen-1-yl)methylene)amino)pyrimidine-4,6-diol derived from 2-amino-4, 6-dihydroxypyrimidine and 2...
Show More
Research Article
Synthesis, Experimental Characterizations and Theoretical Study of the Chemical Reactivity of Coumarin-6-yl Acetate in Gas and Solvent Phases
Issue:
Volume 13, Issue 1, February 2025
Pages:
11-32
Received:
23 December 2024
Accepted:
9 January 2025
Published:
24 January 2025
Abstract: The first objective of the study is based on experimental characterization of the studied compound. The synthetization process of C11H8O4 (I) involved the O-acetylation of 6-hydroxycoumarin with acetic anhydride, utilizing diethyl ether as a solvent and pyridine as a base. The obtained structure was characterized by both spectroscopic analyses such as ESI-MS, FT-IR, 1H and 13C NMR analysis and by single-crystal X-ray diffraction studies. In the latter case, we employed direct methods to solve the structure of (I) and subsequently refined to a final R value of 0.054 for 1896 independent reflections. In the structure, C—H•••O hydrogen bonds connect the molecules into R22 (8) dimers, which are linked together by C—H•••O interactions, forming layers parallel to the bc crystallographic plane. Similarly, the crystal structure is sustained by π–π interactions between neighboring rings, with inter-centroid distances lower than 3.8 Å. The second objective of the study is to use theoretical calculation methods to analyze the effect of solvent polarity on the energy gap of the boundary molecular orbitals and the overall chemical reactivity of coumarin-6-yl acetate in order to provide a better understanding of stability and reactivity. A series of density functional theory computations were achieved with B3LYP/6-311++G(d,p) basis set in both gas and solvent phases. In addition to the dipole moment, the natural bond orbital charge distribution was estimated in toluene, tetrahydrofuran (THF) and benzene solvents. The calculations were conducted utilizing the Gaussian 09 software, and the outcomes exhibited that the solvents have an influence on the optimized parameters. Furthermore, dual and local reactivity indices as Fukui functions from the natural bond orbital (NBO) charges were estimated in order to have a better comprehension of the electrophilic and nucleophilic regions, as well as the chemical activity of (I). The obtained dipole moment in the gas phase is 6.03 Debye and those in the presence of the solvents are 7.89, 6.87, 7.51 and 6.83 Debye for water, toluene, THF and benzene, respectively. Additionally, the global chemical reactivity parameters exhibit variation contingent on the molecular compound and polarity of the solvents, making this an important consideration in the selection of appropriate solvents for a given chemical reaction. The studied compound shows higher stability in the benzene solvent evidenced by an EHOMO-ELUMO energy gap of 9.48 eV, while its low stability is observed in the gas phase with an EHOMO-ELUMO energy gap of 6.64 eV.
Abstract: The first objective of the study is based on experimental characterization of the studied compound. The synthetization process of C11H8O4 (I) involved the O-acetylation of 6-hydroxycoumarin with acetic anhydride, utilizing diethyl ether as a solvent and pyridine as a base. The obtained structure was characterized by both spectroscopic analyses such...
Show More
