Thermodynamic Characterization of Phase Transitions of (Hexafluoroacetylacetonato)(cyclooctadiene-1,5)silver
摘要
New data are obtained on the thermal behavior and processes of vaporization and melting of (hexafluoroacetylacetonato)(cyclooctadiene-1,5)silver, [Ag(cod)(hfac)]n (n = 1, 2). The dimeric form of the complex is synthesized and characterized. The condensed phase is studied via differential scanning calorimetry plus thermogravimetric and differential thermal analysis. The thermal stability and qualitative volatility are assessed, and the temperature, enthalpy, and entropy of melting are determined for the complex. It is shown that the compound is highly sensitive to heating, preventing the experimental determination of reliable thermodynamic characteristics. Thermodynamic characteristics of the evaporation of these chelates are calculated using standardized values of enthalpies and entropies of the sublimation and melting of similar heteroligand complexes of copper(I) and iridium(I). The data are used to construct structure–volatility correlations that allow estimates of the required phase transitions of the target silver complex. An approach to evaluating the thermodynamic properties of complexes of the composition [M(cod)(β-dik)]n is proposed to determine the optimum conditions for depositing coatings that contain metal.