Molybdenum(III) bromide explained

Molybdenum(III) bromide is the inorganic compound with the formula MoBr₃. It is a black solid that is insoluble in most solvents but dissolves in donor solvents such as pyridine.

Preparation

Molybdenum(III) bromide is produced by the reaction of elemental molybdenum and bromine at 350C.^[1]

2 Mo+3 Br _{2} \longrightarrow2 MoBr _{3} It can also be prepared from the reduction of molybdenum(IV) bromide with molybdenum metal, hydrogen gas, or a hydrocarbon.^[2]

It has a structure consisting of infinite chains of face-sharing octahedra with alternatingly short and long Mo-Mo contacts. The same structure is adopted by the tribromides of ruthenium and technetium.^{[3] [4]} In contrast, in the high temperature phase of titanium(III) iodide, the Ti---Ti separation is invariant.

References

1. F. Hein, S. Herzog "Molybdenum(III) Bromide" in Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. Vol. 1. p. 1407.
2. Book: Perry, Dale L.. Handbook of Inorganic Compounds. Taylor & Francis. 2011. 978-1-4398-1461-1. 2nd. Boca Raton. 279.
3. Dietrich Babel: Die Verfeinerung der MoBr₃-Struktur (Refinement of the MoBr₃-Structure) In: Journal of Solid State Chemistry. 1972, volume 4, S. 410–416, .
4. Order-Disorder Transformation in RuBr₃ and MoBr₃: A two-Dimensional Ising Model" Merlino, S.; Labella, L.; Marchetti, F.; Toscani, S. Chemistry of Materials 2004, volume 16, p3895-p3903