Palladium(II) beta-diketonates: Volatility and energy of the crystal lattice

The Knudsen effusion method was used to measure the temperature dependence of the saturated vapor pressure for the palladium(II) beta-diketonates cont aining different sets of the terminal substituents in the ligand: CF3, CH3, C(CH3)(3), C(OCH3)(CH3)(2), and C6H5 Standard thermodynamic Delta H-T(0) a nd Delta S-T(0) of evaporation processes were calculated. The molecular pac king and intermolecular interactions in crystals were considered on the bas is of the structural data. The atom-atomic potential method was employed to determine the van der Waals energy of the crystal lattice. Comparison of t he calculated E-cryst with the experimental Delta H-sub1(0) showed that the suggested methods adequately describe the tendency in the volatility chang e in the palladium(II) beta-diketonates series, in whose crystals the molec ules, in addition to the van der Waals forces, are bound by weak specific i nteractions.