Stibine (SbH3): properties, preparation, uses and safety

Structure and physical character

The SbH3 molecule has a three‑bonded antimony centre with a lone pair, giving it a trigonal‑pyramidal shape similar to other group 15 hydrides. Because antimony is relatively heavy, the molecule is volatile but thermally less stable than its lighter congeners. Its bonding can be described in different ways: some treatments emphasize antimonide character (antimonide-like), others stress covalent Sb–H interactions (hydride-like), and conventional ionic descriptions are sometimes used for teaching (alternative ionic description).

Synthesis and chemical behaviour

In the laboratory stibine is typically generated by the reduction of antimony(III) compounds or by acidifying metal antimonides; it can also be produced by hydride transfer from strong reductants. It is chemically reactive: readily oxidized in air and prone to decomposition to elemental antimony and hydrogen at modest temperatures. Compared with phosphine and arsine, SbH3 is generally less stable and more prone to breakdown, following the expected trend downward the group.

Uses and importance

Practical uses of stibine are limited. It appears occasionally as a reagent in specialized chemical syntheses and can serve as a gaseous antimony source in research on film deposition or semiconductor processing where antimony incorporation is required. Because of safety concerns and the availability of other antimony sources, routine industrial use is uncommon. The molecule is also of interest in fundamental studies of heavy‑atom bonding and pnictogen hydride chemistry (antimony centre).

Safety, toxicity and precautions

• Stibine is highly toxic and can damage red blood cells and the respiratory system; exposures must be minimized.
• It is flammable and can ignite in air; storage and experiments require gas handling controls, ventilation and continuous monitoring.
• Standard precautions include use of scrubbers, inert atmospheres, leak detection and emergency procedures; consult material safety resources (hydride ion) and institutional guidelines.

Distinctions: Stibine should not be confused with other antimony compounds such as stibnite (an antimony sulfide mineral) or organoantimony reagents. As the heaviest stable simple pnictogen hydride commonly discussed, it illustrates the trend of decreasing hydride stability moving from nitrogen down to bismuth in group 15.