Thermochemical reactivity of a solvate crystal studied by thermal analysis and in situ X-ray absorption spectroscopy

A solvate compound of rubidium bromoacetate and bromoacetic acid (1:1) was prepared and characterized. Its thermochemical reactivity was studied with thermal analysis (DSC and thermogravimetry combined with mass spectroscopy) and time-resolved in situ X-ray absorption spectroscopy at the K-edges of both bromine and rubidium. The reaction leads first to decomposition of the solvate crystal into bromoacetic acid and rubidium bromoacetate. Bromoacetic acid evaporates, and rubidium bromoacetate eliminates rubidium bromide and partially forms polyglycolide, a polyester. After the completed reaction, crystalline rubidium bromide remains.