The aluminum phosphide It is an inorganic compound formed by an aluminum atom (Al) and a phosphorous atom (P). Its chemical formula is AlP. It is a solid dark gray or, if very pure, yellow. It is an extremely toxic compound for living beings.
Aluminum phosphide reacts with moisture to form phosphine or phosphane PH3, which is a poisonous gas. For this reason, AlP must not come into contact with water. Reacts strongly with acids and alkaline solutions.
It was used in the past to eliminate pests such as insects and rodents in places where cereal grains and other agricultural products were stored. However, due to its high danger, it has been banned in most countries of the world..
Currently, its usefulness in the electronics area is being theoretically investigated using computers that calculate the possibility of obtaining semiconductor AlP nanotubes, that is, extremely small tubes that can transmit electricity only under certain conditions..
Aluminum phosphide is a very dangerous compound, it must be handled with safety implements such as gloves, glasses, respirators and protective clothing..
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The aluminum phosphide AlP is formed by the union of an aluminum atom Al and a phosphorus atom P. The bond between both is covalent and triple, therefore it is very strong.
Aluminum in AlP has an oxidation state of +3 and phosphorus has a valence of -3.
- Aluminum phosphide
Dark gray or dark yellow or green crystalline solid. Cubic crystals.
57.9553 g / mol
2550 ºC
2.40 g / cm3 at 25 ° C
Decomposes in water.
Reacts with moisture to give phosphine or phosphane PH3 which is a flammable and poisonous compound. Phosphine or phosphane spontaneously ignites on contact with air, except if excess water is present.
The reaction of aluminum phosphide with water is as follows:
Aluminum Phosphide + Water → Aluminum Hydroxide + Phosphine
AlP + 3 HtwoO → Al (OH)3 + PH3↑
The commercial presentations have aluminum carbonate Altwo(CO3)3 to prevent phosphine autoignition that occurs when AlP comes into contact with moisture in the air.
AlP is stable when dry. Reacts violently with acids and alkaline solutions.
Aluminum Phosphide AlP does not melt, sublime, or thermally decompose at temperatures as high as 1000 ° C. Even at this temperature, its vapor pressure is very low, that is, it does not evaporate at that temperature..
When heated to decomposition it emits toxic phosphorus oxides. In contact with metals it can emit flammable hydrogen gases Htwo.
When it is pure it shows a yellowish coloration, when it is mixed with residues of the preparation reaction it presents a color from gray to black..
Its low volatility excludes it from having any odor, so the garlic smell that it sometimes emits is due to phosphine PH3 that forms in the presence of moisture.
Aluminum phosphide can be obtained by heating a mixture of powdered aluminum metal (Al) and red phosphor (P) element.
Due to the affinity of phosphorus (P) for oxygen (Otwo) and that of aluminum (Al) by oxygen and nitrogen (Ntwo), the reaction must be carried out in an atmosphere free of these gases, for example in an atmosphere of hydrogen (Htwo) or natural gas.
The reaction is started by rapidly heating a zone of the mixture until the reaction starts, which is exothermic (heat is produced during the reaction). From that moment the reaction proceeds rapidly.
Aluminum + Phosphorus → Aluminum Phosphide
4 Al + P4 → 4 AlP
Aluminum phosphide was used in the past as an insecticide and as a rodent killer. However, although it has been banned for its toxicity, it is still used in some parts of the world..
It is used for fumigation in confined spaces where processed or unprocessed agricultural food products (such as cereals), animal feed and non-food products are found.
The goal is to control insects and rodents that attack stored items, whether edible or not..
It allows to control rodents and insects in non-domestic, agricultural or non-agricultural areas, spraying outdoors or in their burrows and nests to prevent them from transmitting certain diseases.
Its form of use consists of exposing AlP to air or humidity, since phosphine or phosphane PH is released.3 that damages many organs of the pest to be eliminated.
Aluminum phosphide AlP is used as a source of phosphine or phosphane PH3 and is being used in semiconductor research.
Theoretical studies have been carried out on the formation of aluminum phosphide AlP nanotubes. Nanotubes are very small and very thin cylinders that can be visible only with an electron microscope..
Theoretical studies carried out through computational calculations show that the impurities that could be added to the AlP nanotubes could change the theoretical properties of these.
For example, it is estimated that adding boron (B) atoms to AlP nanotubes could turn them into semiconductors type-p. A semiconductor is a material that behaves as a conductor of electricity or as an insulator depending on the electric field to which it is subjected.
And a semiconductor type-p It is when impurities are added to the material, in this case AlP is the starting material and the boron atoms would be the impurities. Semiconductors are useful for electronics applications.
Some scientists have performed calculations to determine the effect of changing the crystal lattice structure of AlP nanotubes from hexagonal to octahedral..
They found that manipulation of the crystal lattice structure could be used to fine-tune the conductivity and reactivity of AlP nanotubes and design them to be useful for electronics and optics applications..
Contact with Aluminum Phosphide can irritate the skin, eyes, and mucous membranes. If swallowed or inhaled it is toxic. Can be absorbed through the skin with toxic effects.
If AlP comes into contact with water it reacts and forms phosphine or phosphane PH3 which is extremely flammable as it ignites in contact with air. Hence it can explode. In addition, phosphine causes the death of humans and animals.
As aluminum phosphide is an inexpensive pesticide, its use is a common cause of poisoning in people and carries a high mortality rate.
It reacts with the humidity of the mucous membranes and with the hydrochloric acid HCl in the stomach, forming the very toxic phosphane gas PH3. Therefore, by inhalation and by ingestion, phosphine is formed within the body, with fatal effects..
Its ingestion causes gastrointestinal tract bleeding, cardiovascular collapse, neuropsychiatric disorders, respiratory and kidney failure within a few hours..
AlP is very toxic to all terrestrial and aquatic animals.
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