Figure 3: Thermal stability of compound 1.

(a) Thermogravimetric analysis (TGA) in nitrogen (blue trace) and air (red trace) shows no weight loss until 360 °C, suggesting that no solvent was included in the crystal structure of 1. Between 360 and 400 °C, compound 1 loses ~11% of its weight regardless of the carrier gas. Beyond 400 °C, slow decomposition of the material ensues under nitrogen, and much faster one under air. (b) Variable temperature powder X-ray diffraction (PXRD) revealed no change in structure until at least 250 °C. Beyond that temperature, an irreversible phase change occurs. Structure of this new crystalline phase was not determined.