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 β-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.