Equation has the form of the
Equation (3) has the form of the standard equation of a line (y = mx + b ) in which logmsubT is y and 1T is x. Thus, the slope of these plotted values determined the enthalpy of sublimation, ΔHsub as seen in Fig. 3. Each point was computed by evaluating the slope in the isotherms of the TGA as seen in Fig. 4. It is worth noting that PF 299804 the mass loss is 20% or less through 200 °C for all the compounds ( Fig. 5) as higher mass loss could lead to errors due to significant variation in surface area which would alter the sublimation rate. The derivative mass loss ( Fig. 5 in blue) emphasizes the changes in sublimation rate associated with the increasing temperature where strong peaks can be seen as temperature regions for decomposition. The 45–180 °C range is favorable in terms of overall mass loss and presents a reasonable range of smoothness ( Fig. 6, compound 4a). The first significant mass loss at lower temperatures (ca. 50 °C) is due from the loss of residual pentane solvent that was present in the crystalline solids. As shown in Fig. 6, larger mass losses of dichloro-bis[4-(phenylamido)pent-3-en-2-one]-hafnium (4a) are evident at temperatures in excess of 120 °C, which are likely due to decomposition; hence, we chose the temperature range of 67–120 °C (Figs. 3 and 7) to calculate the sublimation enthalpy for our compounds, since this region represents linear regimes for the computation of enthalpies of sublimation for complexes, 4a–d.