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]

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. From the 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. (c) 2008 Elsevier B.V. All rights reserved.