Synthesis, experimental and DFT characterization of the 2-((E)-(2-[(E)-2,3-Dihydroxybenzylideneamino]-5-methylphenyl)iminiomethyl)-6-hydroxyphenolate and its Ni(II) and Cu(II) complexes
| Autor: | Ali Morsali, S. Ali Beyramabadi, Razieh Sanavi-Khoshnood, Mahdi Khorsandi-Chenarboo, Bahareh Esmaeili, Maryam Khashi, Azar Gharib |
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| Rok vydání: | 2017 |
| Předmět: |
Schiff base
010405 organic chemistry Chemistry Ligand Chemical shift Organic Chemistry 010402 general chemistry 01 natural sciences Tautomer 0104 chemical sciences Analytical Chemistry Inorganic Chemistry chemistry.chemical_compound Crystallography Deprotonation Atomic orbital Computational chemistry Density functional theory Spectroscopy Natural bond orbital |
| Zdroj: | Journal of Molecular Structure. 1146:620-628 |
| ISSN: | 0022-2860 |
| DOI: | 10.1016/j.molstruc.2017.06.050 |
| Popis: | Herein, the 2-((E)-(2-[(E)-2,3-Dihydroxybenzylideneamino]-5-methylphenyl)iminiomethyl)-6-hydroxyphenolate H2L Schiff base and its Ni(II) and Cu(II) complexes were synthesized. In addition to experimental characterization, their optimized geometries, tautomerism of the H2L, assignment of the IR bands and NMR chemical shifts, Fukui functions and the Natural Bond Orbital (NBO) analysis were computed by employing the density functional theory (DFT) methods. The H2L salen-type Schiff base can exist as mixture of four possible tautomers, tautomerization of which has low barrier energy in methanol solution. For complexation, the H2L loses two phenolic protons to produce the L2− species, which acts as a dianionic tetradentate ligand. Based on the Fukui functions, the two deprotonated phenolic oxygens and two azomethine nitrogens are the four donating atoms and occupy the four coordination positions in the square-planar structure of the Ni(II) and Cu(II) complexes. In comparison with the its free form, the coordinated ligand shows a more planar structure in the optimized geometries of the complexes. The high-energy gaps of the frontier orbitals confirm that all three investigated compounds are stable. |
| Databáze: | OpenAIRE |
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