Thermodynamics Research Center / ThermoML | Thermochimica Acta

Temperature dependence vapour pressure measurements of Mg(tmhd)2(tmeda) [(tmhd = 2,2,6,6-tetramethyl-3,5-heptanedione, tmeda =N,N,N ,N -tetramethylethylenediamine]

Maria, M.[Mathew], Selvakumar, J., Raghunathan, V. S., Mathew, T.[Tom], Nagaraja, K. S.
Thermochim. Acta 2008, 474, 1-2, 87-90
ABSTRACT
The reaction between the magnesium beta-diketonate complex Mg(tmhd)2(H2O)2 and 1 equiv. of N,N,N',N'- tetramethylethylenediamine (tmeda =Me2NCH2CH2NMe2) in hexane at room temperature yielded Mg(tmhd)2(tmeda). The standard enthalpy of sublimation (83.2+-2.3 kJ mol-1) and entropy of sublimation (263+-6.3 J mol-1 K-1) of Mg(tmhd)2(tmeda) were obtained from the temperature dependence vapour pressure, determined by adopting a horizontal dual arm single furnace thermogravimetric analyser as a transpiration apparatus. Fromthe observed melting point depression DTA, the standard enthalpy of fusion (58.3+-5.2 kJ mol-1) was evaluated, using the ideal eutectic behaviour of Mg(tmhd)2(tmeda) as a solvent with bis(2,4-pentanedionato)magnesium(II), Mg(acac)2 as a non-volatile solute.
Compounds
# Formula Name
1 C10H14MgO4 bis-2,4-pentanedionato magnesium
2 C28H54MgN2O4 magnesium bis-2,2,6,6-tetramethyl-3,5-heptanedionate, N,N,N',N'-tetramethylethylenediamine complex
Datasets
The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type Compound-# Property Variable Constraint Phase Method #Points
  • POMD
  • 2
  • Molar enthalpy of transition or fusion, kJ/mol ; Crystal
  • Crystal
  • Liquid
  • Air at 1 atmosphere
  • Cryoscopy
  • 1
  • POMD
  • 2
  • Vapor or sublimation pressure, kPa ; Crystal
  • Temperature, K; Crystal
  • Crystal
  • Gas
  • Transpiration method
  • 6
  • POMD
  • 1
  • 2
  • Solid-liquid equilibrium temperature, K ; Liquid
  • Mole fraction - 2; Liquid
  • Pressure, kPa; Liquid
  • Liquid
  • Crystal - 2
  • DTA
  • 5