Co-crystal structures and Hirshfeld surface analysis of mesitylene and/or p-xylene solvated pseudopolymorphs of fully fluorinated Pd(II) complex

The fully fluorinated complex, Pd(L)₂, comprised of one Pd²⁺ ion and two ligands, namely bis(pentafluorobenzoyl)methanido⁻ (L), was well crystallized with mesitylene (C₉H₁₂) and p-xylene (C₈H₁₀) as guest molecules to form unique co-crystals, Pd(L)₂·2C₉H₁₂ and Pd(L)₂·2C₈H₁₀, respectively, using a chloroform or ethyl acetate solution. In the crystals, the π-planes of the guest molecules closely interacted with the pentafluorophenyl groups of the complex through an π···π-hole interaction. By the combination of two guest molecules, a new crystal, Pd(L)₂·2C₉H₁₂·C₈H₁₀, was obtained and two mesitylene and one p-xylene molecules are quantitatively inserted into the crystal without any structural disorder, showing the good affinity of the guest molecules and the flexible shape changes of the complex.