Crystal structures and charge distribution of partially-fluorinated β-diketonate copper(II) complexes based on Hirshfeld surface analysis and DFT calculations

Two partially-fluorinated coordination complexes, C₃₀H₂₀CuF₂O₄ (1) and C₃₀H₁₈CuF₄O₄ (2), were prepared and the corresponding crystals, 1 with a benzene solvate (1•C₆H₆) and 2, were obtained from a benzene-dichloromethane solution. The crystallographic studies and the Hirshfeld surface analysis of the crystals showed the metal⋯π interactions through an electrophilic property of the Cu ions and the remarkable CH⋯π interactions between the phenyl substitutions; the most important contributions for the crystal packing for 1 in 1•C₆H₆ are from the C⋯H/H⋯C (36.8%), H⋯H (34.0%), and F⋯H/H⋯F (10.4%) interactions but those for 2 are from the H⋯H (28.8%), F⋯H/H⋯F (22.9%), and C⋯H/H⋯C (19.2%). A density functional theory (DFT) calculation using the optimized structures from the crystal data clearly showed the proportion of the electron-withdrawing effects of the fluorine substitution and the corresponding effects on the central metal ions and the other aromatic rings.