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چکیده
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A new tetranuclear cubane-like complex, [Ni4(L)4Cl4(H2O)3(EtOH)]•(H2O), has been synthesized from the reaction of simple metal salt with bidentate ligand 2-hydroxymethylpyridine (LH), and its crystal structure, spectroscopic and chromotropic properties have been studied. The complex possessed a [Ni4O4] core comprising a distorted cubane arrangement, of which four nickel(II) ions were bridged by μ3-alcoholic moieties. Each nickel(II) ion was coordinated to three μ3-alkoxo oxygen atoms, one pyridine nitrogen atom ligand and one chloride ion. The peripheral ligation was completed by a terminal oxygen atom of water or ethanol ligands, which participated in intramolecular hydrogen bonding interactions. Chromotropism properties of the complex including solvato-, thermo- and ionochromism were investigated in detail. The complex displayed strongly pronounced ionochromism and shows high-sensitive and selective towards CN- and SCN- anions in presence of other halides and pseudo-halides. The solvatochromic property of the complex was analyzed by multi-parametric equation using SPSS/PC software. The stepwise multiple linear regression method demonstrated that the acceptor power of the solvent plays the most important role in the observed negative solvatochromism of the compound. It shows reversible thermochromism property in solution due to loss of the weakly coordinated water and ethanol molecules from the nickel (II) units.
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