Synthesis, structure, theoretical studies, and fluorescence properties of two multinuclear Cu(II) bis(salamo)-like complexes

New di- and tetranuclear Cu(II) complexes, [Cu-2(HL)Cl-2(MeOH)]center dot MeOH center dot 2CH(2)Cl(2) (1) and [Cu-4(L)(2)(MeOH)(2)](NO3)(2)center dot EtOH (2), have been synthesized from CuCl2 center dot 2H(2)O, Cu(NO3)(2)center dot 3H(2)O and a symmetric 5-bromosalicylaldehyde-decorated bis(salamo)-like ligand (H3L, (1E,3E)-2-hydroxy-5-methylisophthalaldehyde O,O-di(2-((((E)-5-bromo-2-hydroxybenzylidene)amino)-oxy)ethyl)dioxime), and characterized by elemental analyses, IR and UV-vis spectra. Single crystal structure analyses showed a dinuclear Cu(II) structure for 1 and a tetranuclear Cu(II) structure for 2. In 1, two Cu(II) ions are on one side of the double N2O2 cavities, and the phenol proton in the other cavity is attached. In 2, four Cu(II) ions are located in four N2O2 cavities of two fully deprotonated L3- units, giving a centrosymmetric double helix structure. The Hirshfeld surfaces analyses, Interaction Region Indicator (IRI), and DFT computations of H3L, 1, and 2 were studied. In addition, the electrochemical and fluorescence properties of 1 and 2 were also investigated. [GRAPHICS] .