Search

The heteroleptic tetranuclear copper(II) complex, [Cu(II)4(µ2-Cl)3 -(µ1-Cl)3 (µ- C2O4- κ 4 O1, O2: O1 ′, O2′) - (µ1-1-4-dioxane) - (terpy-κ3 N, N′, N″)]; have been synthesized and its crystal structure was solved using single crystal X-ray diffraction method under ambient conditions. Each Cu(II) ion is in a highly distorted square-pyramidal coordination environment in the title complex. In the crystal, the complex molecules are linked by C—H…Cl and C—H…O hydrogen bonds, forming propagating chains along the [110] direction. This complex exhibits a π-π interaction resulting from an overlap between pyridine rings of molecules A and B [intercentroid distance = 3.921(9)A, 3. 813(9)A and 3.724(9)A] leading to the formation of a supramolecular framework. A detailed analysis of Hirshfeld surfaces and fingerprint plots show that van der Waals interactions constitute a further significant contribution to the intermolecular interactions, with H…H contacts accounting for 33.1% of the surface. In addition, the geometrical optimization of the tetranuclear Cu(II) complex was done by electronic structure method using density functional theory (DFT) to identify the active sites and to explore the chemically reactive parameters of the molecule and the HOMO-LUMO energy gap (0.5916 eV). QTAIM and the NCI index model analyses the vital role of distinct non-covalent interactions in the establishment of a unique structural topology. Furthermore, AChE/BChE and tyrosinase activity methods have been used to estimate the in vitro anti-Alzheimer effect of the synthesized complex, which has shown a potent AChE/BChE inhibition.

Two new complexes [MnIII(HL)2(acac)] and [MnII(HL)2]n have been obtained by reacting manganese(III) acetylacetonate monohydrate or manganese(II) chloride monohydrate with 2-salicylichydrazono-1,3-dithiolane ligand (H2L). Both compounds have been fully characterized by spectroscopic methods and single crystal X-ray diffraction. In the solid state, the molecular packing are described and discussed in term of weak H-bonds and short contacts. The unprecedented bridging coordination mode of this ligand lead to the first 2-salicylichydrazono-1,3-dithiolane-bridged coordination polymer [MnII(HL)2]n. The EPR spectrum of this compound was obtained with g ≈ 2.07, corresponding to a manganese ion (+II) in octahedral high-spin coordination sphere. The MnII complex exhibit paramagnetic behavior corresponding to quasi-isolated metal centers.

The title compound, [Na(C10H9.5N2O2S2)2(H2O)], is a molecular sodium complex with N′-(1,3-dithiolan-2-yl)-2-hydroxybenzohydrazide ligands with the negative charge spread evenly over both, and a water molecule. The NaI ion coordination is distorted trigonal–bipyramidal, formed by two N and three O atoms, with the NaI ion lying on a twofold rotation axis. Intramolecular N—H...O hydrogen bonds occur. Molecules pack as discrete units and the crystal packing is stabilized by strong O—H...O hydrogen bonds, which give rise to chains along [010]; the chains are interlinked by strong O—H...O hydrogen bonds.