Abstract: New data are obtained on the thermal behavior and sublimation and melting of (pivaloyltrifluoroacetonato)( cyclooctadiene-1,5)iridium {[Ir(cod)(ptac)]}. The condensed phase is studied via differential scanning calorimetry, and the complex’s temperature of melting is determined along with its enthalpy and entropy of fusion: Tmelt = 405.9 ± 0.5 K; (Tmelt) = 20.4 ± 0.3 kJ mol−1; ; (Tmelt) = 50.3 ± 0.7 J mol−1 K−1. The temperature dependence of the saturated vapor pressure of [Ir(cod)(ptac)] in the 363– 397 K range of temperatures is obtained from the flow. The thermodynamic characteristics of sublimation are calculated at the average temperature of the experimental range and 298.15 K: (Tav) = 102.0 ± 1.8 kJ mol−1; (Tav) = 188.5 ± 3.3 J mol−1 K−1; (298.15 K) = 107.3 ± 2.9 kJ mol−1; and (298.15 K) = 204.1 ± 5.7 J mol−1 K−1. The resulting values are compared to those of similar compounds of iridium(I) and other β-diketones, [Ir(cod)(β-dik)]. The results form the basis for developing a way of assessing the thermodynamic properties of complexes [M(cod)(β-dik)], which is needed when compounds (e.g., [Ag(cod)(β-dik)]) are hypersensitive to heating and it is impossible to determine reliable thermodynamic characteristics experimentally in order to establish the optimum conditions for the gas-phase deposition of etal-containing coatings.

Cite: Zherikova K.V. , Vikulova E.S. , Sysoev S.V. , Zelenina L.N. , Morozova N.B.
Thermodynamic Study of the Phase Transitions of (Pivaloyltrifluoroacetonato)cyclooctadiene-1,5) Iridium
Russian Journal of Physical Chemistry A. 2024. V.98. N14. P.3429–3434. DOI: 10.1134/S0036024424702996 WOS OpenAlex

Dates:

Submitted:	Aug 20, 2024
Accepted:	Sep 13, 2024
Published print:	Feb 11, 2025

Identifiers:

Web of science:	WOS:001419992600005
OpenAlex:	W4407368760

Citing: Пока нет цитирований

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