Mono, di and heptanuclear metal(II) complexes based on symmetric and asymmetric tetradentate Salamo-type ligands: Syntheses, structures and spectroscopic properties

Mono, di and heptanuclear metal(II) complexes with chemical formulae [Cu(L1)] (1), [Co2(L2)2]·2CH3CN (2) and [Ni7(L3)3(μ3-OEt)2(μ3-OH)6(EtOH)6] (3) have been synthesized by variational tetradentate Salamo-type ligands based on 3,5-dichlorosalicylaldehyde, and characterized by elemental analyses, FT-IR, UV–Vis spectra and X-ray crystallography. The Cu(II) complex 1 is a mononuclear complex with tetracoordinate Cu(II) atom lies in the N2O2 coordination sphere. The Co(II) complex 2 is a dinuclear complex with a central Co2O2 bridged unit via CoO bonds to form a head-to-head dimer, the pentacoordinate Co(II) atoms (Co1 and Co2) have a distorted square pyramidal (τ1 = 0.454) and trigonal bipyramidal (τ2 = 0.538) geometries, respectively. Interestingly, the Ni(II) complex 3 is a novel heptanuclear complex with an unprecedented 3:7 ligand to metal stoichiometry. Furthermore, fluorescence properties of the Cu(II) and Ni(II) complexes have been studied.

Mono, di and heptanuclear metal(II) complexes with chemical formulae [Cu(L1)] (1), [Co2(L2)2]·2CH3CN (2) and [Ni7(L3)3(μ3-OEt)2(μ3-OH)6(EtOH)6] (3), have been synthesized by variational tetradentate Salamo-type ligands based on 3,5-dichlorosalicylaldehyde, and characterized structurally.Figure optionsDownload as PowerPoint slide