Copper(II) and lanthanoid(III) complexes of a new β-diketonate ligand with an appended non-coordinating phenol group

New mononuclear compounds of the ligand 1-(2-hydroxyphenyl)-3-phenylpropane-1,3-dione (H2L) with Cu(II) and several lanthanoid(III) ions, where Ln(III) = Pr, Nd, Eu, Gd, have been synthesized and characterized by spectroscopic methods and X-ray crystal structure determinations. In all compounds, the ligand coordinates in a bidentate chelating manner, using the diketone function. In the [Cu(HL)2], the coordination geometry of Cu(II) ion is slightly distorted square-planar; two strong intramolecular (OH⋯O) hydrogen-bonding interactions are established between the phenolate group and the neighboring ketone function. The lanthanoid(III) compounds have the general formula [Ln(HL)3(CH3OH)2] · CH3OH · 2H2O; the lanthanoid(III) ion (Ln) is eight-coordinated and the coordination geometry is based on a distorted square-antiprism. In addition to the intramolecular hydrogen bonding (OH⋯O), intermolecular hydrogen-bonding interactions are also present between the coordinated methanol molecule and the non-coordinated methanol molecule giving rise to a three-dimensional network.

Graphical abstractMononuclear copper(II) and lanthanoid(III) (Ln = Pr, Nd, Eu, Gd) compounds from a new β-diketone ligand, namely 1-(2-hydroxyphenyl)-3-phenylpropane-1,3-dione have been synthesized and characterized. The structural studies show that in all compounds, the ligand coordinates in a bidentate chelating manner, using the diketone function.Figure optionsDownload full-size imageDownload as PowerPoint slide