Promethium(III) iodide explained

Promethium(III) iodide is an inorganic compound, with the chemical formula of PmI₃. It is a red radioactive solid with a melting point of 695 °C.

Preparation

Promethium(III) iodide is obtained by reacting anhydrous hydrogen iodide and promethium(III) chloride at a high temperature:

PmCl₃ + 3 HI → PmI₃ + 3 HCl^[1]

From the reaction of a HI-H₂ mixture and promethium oxide (Pm₂O₃), promethium(III) iodide cannot be produced, and only promethium oxyiodide (PmOI) can be obtained. Promethium oxide reacts with molten aluminum iodide at 500°C to form promethium iodide.^{[2] [3]}

Notes and References

1. W. R.. Wilmarth. G. M.. Begun. R. G.. Haire. et al. Raman spectra of Pm₂O₃, PmF₃, PmCl₃, PmBr₃ and PmI₃.. Journal of Raman Spectroscopy. 2005. 19. 4.
2. Salzberg . H. W. . 1958 . Gmelins Handbook of Inorganic Chemistry . Journal of the Electrochemical Society . 105 . 6 . 112C . 10.1149/1.2428830 . 0013-4651.
3. Weigel. Fritz. Radiochimica Acta. Die Chemie des Promethiums.... 591. more complete reference required