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A flexible octadentate C-shaped bis(salamo)-based ligand (H4L) with two different coordination environments, which can react with different metal salts to form heterotrinuclear zinc(II)-lanthanide(III) bis(salamo)-based complexes [Zn2La(L)(µ2-OAc)2(η2-NO3)]·2CH2Cl2 (1) and [Zn2Ce(L)(µ2-OAc)2(η2-NO3)] (2). The detailed analysis of Hirshfeld surfaces and fingerprints compares the intermolecular interactions, which are very important for the construction of different supramolecular structures. The molecules are connected by the combination of C–H···O hydrogen bonds to form an infinite 1D supramolecular chain. [ABSTRACT FROM AUTHOR]

A homo-dinuclear Cu(II) complex [Cu2(L)2] with the stoichiometric ratio of Cu(II) : (L)2– = 2 : 2 was synthesized by the reaction of the ligand (4-methyl-6-aldehyde-6′-methoxy-2,2′-[ethylenediyldioxybis(nitrilomethylidyne)]diphenol) with Cu(OAc)2·H2O in the mixed CH2Cl2–MeOMe–EtOH solution (an unexpected ligand is the intermediate of condensation reaction of starting ligand with acetone). The Cu(II) complex was characterized by elemental analysis, IR, UV-Vis and X-ray crystallography. The Cu(II) complex crystallizes in monoclinic space group P21/n and consists of two Cu(II) atoms and two completely deprotonated ligand (L)2– units. Through the analysis of intermolecular interactions, the Cu(II) complex units can form a 2D supramolecular structure through intermolecular hydrogen bonds and C–H···π interactions, respectively, meanwhile, the molecular interactions were quantitatively studied by Hirshfeld surfaces analyses. The fluorescence properties and DFT calculations were performed. [ABSTRACT FROM AUTHOR]

Two new trinuclear Ni(II) complexes, [{Ni(L)(DMF)(μ-OAc)}2Ni] (1) and [{Ni(L)(EtOH)(μ-OAc)}2Ni]·2CH2Cl2 (2), have been successfully synthesized from a new asymmetric salamo-based hexa-dentate chelating ligand (H2L) and Ni(OAc)2·4H2O, and characterized by elemental analysis, IR and UV-Vis spectra, and X-ray crystallography. The binding ratio of H2L and Ni(II) ion has been confirmed by UV-Vis titration. All Ni(II) atoms are hexa-coordinated, and the complexes have octahedral configuration, though with difference in the solvent molecules (DMF/EtOH) involved in the coordination, composition of the hydrogen bond and chemical stability. This conclusion is confirmed by Hirshfeld surfaces analyses and Density Functional Theory (DFT). [ABSTRACT FROM AUTHOR]

A novel tetranuclear Ni(II) complex [Ni4(L)2(N3)4Cl(MeOH)3]·CH3COCH3 is synthesized via a symmetrical salamo-based ligand H2L, NiCl2·6H2O, and NaN3. The structure is characterized by elemental analyses, IR and UV-Vis spectroscopy, and X-ray diffraction analysis. The X-ray crystal analysis shows that Ni(II) atoms in the Ni(II) complex have distorted octahedral geometries. It is the key factor that the ligand containing 3-position methoxy groups gives rise to the formation of the tetranuclear Ni(II) complex. When anions are used to bridge two Ni2 atoms, there are two symmetrical open cubic structures. The Ni(II) complex forms a 3D supramolecular structure through intermolecular hydrogen bond interactions. Using the Hirshfeld surface to clarify interactions between the molecules, the percentages of C–H/H–C, O–H/H–O, and H–H/H–H contacts are calculated as 19.0%, 15.3%, and 54.0%, respectively. Density functional theory (DFT) studies show that the stability of the Ni(II) complex is much higher than that of H2L. The calculation of the fluorescence titration experiment can give K = 1.05·108 M–1, which further proves the stability of the Ni(II) complex. [ABSTRACT FROM AUTHOR]