STANDARD MOLAR ENTHALPY OF FORMATION OF BIS(2,2,6,6-TETRAMETHYLHEPTANE-3,5-DIONATO) DIOXOURANIUM(VI) IN THE CRYSTALLINE AND GASEOUS STATES - THE MEAN U-O BOND-DISSOCIATION ENTHALPY

• Type: Article in International Scientific Journal
• Date: 1993

Authors

DASILVA, MAVR (Author) FCUP; MONTE, MJS (Author) FCUP; GIERA, E (Author) Other; KAKOLOWICZ, W (Author) Other

Journal

Title: Journal of Chemical Thermodynamics

Vol. 25

Pages: 1263-1272

ISSN: 0021-9614

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 5 Citations

Scopus - 8 Citations

Scientific classification

FOS: Engineering and technology > Mechanical engineering

Other information

Authenticus ID: P-001-MKY

DOI: 10.1006/jcht.1993.1125

Abstract (EN): The standard (po = 0.1 MPa) molar enthalpy of formation, at the temperature 298.15 K, of crystalline bis(2,2,6,6-tetramethylheptane-3,5-dionato) dioxouranium(VI) {uranyl(VI) dipivaloylmethanate, UO2(DPM)2}, was determined by solution-reaction calorimetry as -(2169.9±7.6) kJ·mol-1. The vapour pressure of the crystal, as function of the temperature, was measured using the Knudsen mass-loss effusion technique and the standard molar enthalpy of sublimation, at the temperature 298.15 K, was derived as (156.9±1.9) kJ·mol-1. From these results, the standard molar enthalpy of formation of the complex, in the gaseous state, was derived and the mean uranium(VI)-oxygen bond-dissociation enthalpy for the binding of the ligand to the metal, ¿D¿(U-O), was calculated as (223±10) kJ·mol-1.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 10