Copper(II) complexes containing mixed- chelate ligand, solvatochromism and density functional theory studies

•Two new copper (II) complexes including mixed-chelate ligands were synthesized.•Ligand l acts as tri- and bidentate ligand in different complexes.•One of the complex exhibits solvatochromism.•Statistical analysis showed that salvochromism is due to solvent donor number.•Computational results in three solvents support the proposed solvatochromism.