Common Compounds of Antimony

Antimony

People have been using compounds of antimony for a very long time. Antimony, which wasn’t identified as a chemical component until the Middle Ages, was utilized frequently by alchemists. Antimony sulfide, or stibic stone (Sb2S3), was used by Egyptian women to darken their eyes. Additionally, they created colored glazes for glassware and jewelry using antimony. The old name for the substance, stibium, inspired the antimony chemical symbol.

Compounds

The production of compounds utilized in creating flame-resistant materials is antimony’s most significant use. Its use accounts for a little bit more than 50% of all the antimony. That included antimony oxychloride, antimony trioxide (Sb2O3), antimony trichloride (SbCl3), and antimony pentoxide (Sb2O5). Such substances are added to and sprayed to make it flame-retardant fabric.

Sb(III) and Sb (V) are antimony compounds frequently categorized based on their oxidation state. The more stable oxidation state is +5.

Oxides and hydroxides

When antimony burns in the air, you create antimony trioxide. The compound’s unit is Sb4O6 in the gaseous state, though it polymerizes during condensation. Only after oxidizing with strong nitric acid may antimony pentoxide (Sb4O10) be created.

Another mixed-valence oxide that contains both Sb(III) and Sb(V) is called antimony tetroxide (Sb2O4). The oxides are amphoteric, don’t form clearly defined oxoacids, and combine with acids to generate antimony salts, in contrast to arsenic oxides and phosphorus.

While Sb4O6 and sodium oxide combine to generate sodium antimonite ([Na3SbO3]4), the antimonous acid Sb(OH)3 is unidentified. You can also identify 763 Antimonites made of transition metals. 122 Only the hydrate form of antimonic acid, HSb(OH)6, which forms salts as the antimonate anion Sb(OH)6, is present in nature. The sediment has mixed oxides whenever a solution with this anion is dehydrated. 143 Stibnite (Sb2S3), zinkenite, jamesonite, pyrargyrite (Ag3SbS3), and boulangerite are just a few of the sulfide-containing antimony ores.

757 Antimony pentasulfide is non-stoichiometric and contains S-S bonds and antimony in the +3 oxidation state. Thioantimonides include [Sb6S10]2 and [Sb8S13]2, among others. 

Halides

SbX5 and SbX3 are two sets of halides that antimony can produce. The chemical compounds SbF3, SbBr3,  SbCl3, and bI3 all have trigonal pyramidal molecular shapes.

Sb2O3 reacts with HF to form the trifluoride, SbF3 produced. 

761–762 Sb2O3 + 6 HF → 2 bF3 + 3 H2O

It’s Lewis acidic and rapidly takes fluoride ions to create the complex anions SSbF−4 and SbF2−5.  SbF3 in liquid form is a poor electrical conductor. Through dissolving Sb2S3 in hydrochloric acid, you create trichloride SbCl3:

2 SbCl3 + 3 H2S from Sb2S3 + 6 HCl

SbF5 and SbCl5 are pentahalides with trigonal bipyramidal molecular structures in the gas phase; however, SbF5 is polymeric in the liquid phase, and SbCl5 is monomeric.

761 SbF5 is a strong Lewis acid that you use to create the superacid fluoroantimonic acid (“H2SbF7”).

Antimony oxyhalides are more frequent than those for phosphorus and arsenic. In strong acids, antimony trioxide dissolves to produce oxoantimonyl molecules such SbOCl and (SbO)2SO4. 

Hydrides, organoantimony, and antimonides compounds

You can generally refer to compounds within this class as Sb3- derivatives. Silver antimonides (Ag 3Sb) and indium antimonide (InSb) are antimonides that antimony can produce with metals.   760 Antimonides of zinc and alkali metals, such as Zn3Sb2 and Na3Sb3, are much more reactive. The antimonides undergo acid treatment to yield the extremely unstable gas stibine, SbH 3: Sb3− + 3 H+ → SbH3.

Additionally, you can create stibine by combining Sb3+ sodium with hydride chemicals like sodium borohydride. At room temp, stibine spontaneously breaks down. Antimony doesn’t react immediately with hydrogen due to the thermodynamic instability of stibine, which has a favorable heat of production. 

Antimony halides are commonly alkylated using Grignard reagents to produce organoantimony compounds. Sb(V) and Sb(III) centers are recognized in various compounds, notably anions, cations, and mixed chloro-organic derivatives. Good examples include cyclic [Sb(C6H5)]n, Sb2(C6H5)4 (containing a Sb-Sb bond), and Sb(C6H5)3 (triphenylstibine). Pentacoordinated organoantimony compounds are widespread; Sb(C6H5)5 and several other related halides are two examples.

Take away

Antimony compounds endanger human health. These substances can irritate both lungs and eyes at low concentrations. They could also result in stomach ulcers, pain, vomiting, and diarrhea. Antimony and its components can potentially harm the heart, kidney, lungs, and liver at larger concentrations. They are deadly at very large dosages.