Titanium(III) bromide explained

Titanium(III) bromide is the inorganic compound with the formula TiBr₃. It is a blue black paramagnetic solid with a reddish reflection. It has few applications, although it is a catalyst for the polymerization of alkenes.

Production and structure

TiBr₃ can be produced by heating the tetrabromide in an atmosphere of hydrogen:^[1]

2TiBr₄ + H₂ → 2TiBr₃ + 2HBrIt can also be produced by comproportionation of titanium metal and titanium tetrabromide.^[2]

Ti + 3TiBr₄ → 4TiBr₃

Two polymorphs of TiBr₃ are known, each exhibiting octahedral Ti centers.^[3]

Reactions

Heating the tribromide gives titanium(II) bromide together with the volatile tetrabromide:^[1]

2 TiBr₃ → TiBr₄ + TiBr₂

The solid dissolves in donor solvents (L) such as pyridine and nitriles to produce 3:1 adducts:

TiBr₃ + 3 L → TiBr₃L₃

Notes and References

1. Book: 10.1002/9780470132371.ch17. Titanium(III) Chloride and Titanium(III) Bromide. 1960. Sherfey. J. M.. Inorganic Syntheses . 57–61. 6. 978-0-470-13237-1.
2. Book: 10.1002/9780470132579.ch69. Inorganic Syntheses. 1989. Stebler. 26. Anton. Leuenberger. Bruno. Güdel. Hans U.. Synthesis and Crystal Growth of A ₃ M ₂ X ₉ (A = Cs, Rb; M = Ti, V, Cr; X = Cl, Br) . 377–385. 978-0-470-13257-9.
3. Troyanov, S. I.; Rybakov, V. B.; Ionov, V. M. "Preparation and crystal structure of titanium tetrabromide, titanium tribromide and titanium(2+) tetrabromoaluminate(1-)" Zhurnal Neorganicheskoi Khimii 1990, vol. 35, 882-7.