Dinuclear copper(II) complexes with bridging oximato group: Synthesis, crystal structure and solvatochromism property

•Two dinuclear copper(II) complexes with oximato ligand have been prepared.•The compounds are soluble in organic solvents and exhibit solvatochromism.•The complexes show positive solvatochromism.•The solvatochromism were analyzed by stepwise multiple linear regression method.•The analysis showed donor number is responsible for solvatochromism phenomenon.

The synthesis, structure, and solvatochromism properties of two new complexes with empirical formula [Cu2L2]X2, are described, where HL stands for 2-(N,N-diisopropyl-2-aminoethyl)imino-3-butanone oximato and X is perchlorate or tetraphenylborate anion. The complexes were characterized by elemental analyses, molar conductance and spectral studies. The binuclear complex [Cu2L2](BPh4)2 was analyzed by X-ray crystallography. In complexes the copper centers are bridged through the oximato NO groups forming a dimer containing a crystallographic twofold symmetry axis. The complexes are solvatochromic and their solvatochromism were investigated by visible spectroscopy. The solvent-dependent absorption maxima, λmax, was analyzed using stepwise multiple linear regression (SMLR) method to find the best model explaining the observed positive solvatochromism. The analysis demonstrated that among different solvent parameters, donor number (DN) is a dominant factor responsible for the shift in the d-d absorption band of the complexes to the higher wavelength with increasing its values.

Graphical abstractThe synthesis, structure, and solvatochromism properties of two dinuclear copper(II) complexes are described. The complexes are solvatochromic and their solvatochromism were investigated by stepwise multiple linear regression computational method. The analysis demonstrated that donor number is responsible for the shift in the d-d absorption band of the complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide