Variable-temperature study of AsH3 – The structure of α-AsH3

The hydrogen compounds of the lighter Group V elements PnH3 (Pn = N, P, As) have been important starting materials for industrial processes for many decades, with phosphine and arsine (PH3 and AsH3) being important for the production of semiconductor materials. The crystal structures of PH3 and AsH3 are unknown. They are, however, of interest as we have shown in previous experiments, that they exhibit polymorphism with at least two (from powder X-ray diffraction) or possibly three (differential scanning calorimetry) different crystallographic phases. Within this experiment we will elucidate the crystal structure of the high-temperature polymorph by growing a single crystal in a capillary directly on the instrument.