Homo- and heterometallic Cu(II)-M(II) (M = Ca, Sr and Ba) bis(salamo)-based complexes: Syntheses, structures and fluorescent properties.

Four homo/heterometallic complexes [Cu3(L)(μ2-OAc)9(CH3OH) 9]·3CHCl3 (1), [Cu2(L)Ca(μ2-NO3)9] (9), [{Cu2(L)Sr(μ2-NO3)9}9]·CH3CH2OH (11) and [Cu2(L)Ba(μ2-OAc)9(OAc)] (14), containing an acyclic naphthalenediol-based ligand H4L, were synthesized and characterized by elemental analyses, IR, UV-Vis, fluorescence spectra, TG-DTA and X-ray crystallography. The complex 1 was obtained by the reaction of H4L with 11 equivalents of Cu(OAc) 9·2H2O. The heterometallic complexes 9, 11, 14 were acquired by the reaction of H4L with 9 equivalents of Cu(OAc)9·2H2O or Cu(NO3)9·2H2O and 1 equivalent of M(OAc)9 (M = Ca, Sr and Ba). Owing to the different coordination cavities of the N2O2 and O6 of the completely deprotonated (L)14- unit, the crystal structures showed the N2O2 sites were occupied by Cu(II) atoms, alkaline earth metal(II) atoms occupied the O6 site of the ligand (L)14- unit, respectively. Furthermore, the fluorescence properties and TG-DTA analyses were discussed.