Cyanide

Introduction

Cyanide contains the a $\mathrm{CN-}$ functional group. The carbon atom that makes up this group, the cyano group, is triple bonded to a nitrogen atom. Cyanide anion and nitrile anion are other names for it. Cyanide can be produced by certain bacteria, algae, and fungi. In addition, it can be found in almonds, spinach, and other foods. When heated up, hydrogen cyanide transforms into a colourless gas with a bitter almond odour. At ambient temperature, it behaves as a colourless or light blue liquid.

Some cyanides, such as sodium & potassium cyanide, are found as a white powder and have an unpleasant almond scent.

What is Cyanide?

Any substance that has the monovalent combining group 𝐶𝑁− is considered cyanide. The cyanide group is found in inorganic cyanides, like sodium cyanide, in the form of the cyanide ion. These substances are reportedly quite hazardous. Organic cyanides are considered nitriles, and in these, we have $\mathrm{CN-}$. The group is further joined to the group that contains carbon by a covalent connection, such as the methyl in methyl cyanide.

About Cyanide

An extremely explosive liquid is hydrocyanic acid, often known as $\mathrm{HCN}$. The Andrussow method, which combines ammonia, methane, & oxygen with a $\mathrm{pt}$ metal catalyst, is used to create $\mathrm{HCN}$. Acrylonitrile, which is required for the creation of synthetic rubber, acrylic fibres, and plastics, may be made using the $\mathrm{HCN}$ product. Consuming $\mathrm{HCN}$ salts or breathing $\mathrm{HCN}$ causes cyanide poisoning.

Nomenclature and Etymology

Organic substances with a $\mathrm{CN-}$ functional group are known as nitriles in the IUPAC nomenclature. Nitriles are thus organic substances. Acetonitrile, often known as methyl cyanide, is one instance of nitrile. Nitriles often don't yield cyanide ions. Cyanohydrin is a functional group made composed of cyanide & hydroxyl linked to a comparable carbon. Cyanohydrins do yield $\mathrm{HCN}$, unlike nitriles. Cyanides are the name for salts with the $\mathrm{CN-}$ion in inorganic chemistry. The cyanide ion does, however, include one atom of carbon, which is not often regarded as organic.

The word "Prussian blue" is derived from the Greek word "kyanos," which means "dark blue," since it was initially produced by burning the pigment called Prussian blue.

Occurrence

Many plants contain cyanides, which are generated by certain fungi, algae, & bacteria. Fruit stones & some seeds also contain significant levels of cyanides. Those of apricots, peaches, & apples, for an instance. Cyanogenic chemicals are chemical substances that emit cyanide. Cyanides are typically found in plants attached to sugar molecules as cyanogenic glycosides, which act as the plant's defence mechanism against herbivores. Cassava roots, a staple vegetable that resembles potatoes and is farmed in tropical regions, also contain cyanogenic glycosides.

Toxicity

Many $\mathrm{CN-}$ is extremely poisonous. The 4th complex in the electron transport system, cytochrome c oxidase, which contains eukaryotic organisms' mitochondria contained in the inner membrane and is hypothesised to be inhibited by the cyanide anion. It binds to the iron within this protein. additionally, the interaction between cyanide and the enzyme inhibits the passage of e through cytochrome-𝐶 to 𝑂. Damage to the electron carriers’ chain, as a result, inhibits the cell from aerobically producing ATP for energy. Particularly impacted are the tissues of the heart & central nervous system, which strongly rely on aerobic respiration.

Antidote

When cyanide and hydroxocobalamin combine, cyanocobalamin is created, which the kidneys can safely remove. The benefit of this approach is that methemoglobin production is prevented. The US Food and Drug Administration granted permission for the Cyanokit antidote kit in the year 2006.

Properties of Cyanide $\mathrm{CN-}$

Chemical formula	$\mathrm{CN-}$
Colour	colourless or light blue
Molecular mass	28.018 g/mol
Conjugate acid	$\mathrm{HCN}$
The melting point of $\mathrm{HCN}$	-13.4 °C
Density of $\mathrm{HCN}$	0.6876 𝑔𝑐𝑚−3

Cyanide Structure $\mathrm{CN-}$

The carbon monoxide ion & molecular 𝑁 are isoelectronic with the cyanide ion. 𝑁 & 𝐶 are bonded together by a triple bond. Carbon carries a significant amount of negative charge.

$\mathrm{CN-}$ Uses (Cyanide)

• Sodium nitroprusside, a cyanide molecule, is largely employed in clinical chemistry as a follow-up test for diabetes patients to assess urine ketone bodies. It is occasionally used to cause a dramatic drop in blood pressure in people during medical crises. Additionally, it is employed in vascular studies as a vasodilator. At the time of World War I, Japanese doctors briefly utilised the copper cyanide combination to treat leprosy and TB.

• Coyotes and other canids are killed in the United States with M44 cyanide devices. Additionally, possums, an imported mammal that endangers the existence of native creatures and causes cattle to contract TB, are the target of cyanide pest management in New Zealand. Possums may develop a fear of the bait, but the use of the cyanide-containing pellets lessens this fear.

Applications of Cyanide Formula

• Mining- Because it helps dissolve these metals and their ores, cyanide is primarily utilised in the mining of gold & silver. The cyanide method contains finely powdered high-grade ore with piles of low-grade ores that have been sprayed with a cyanide mixture.

• Illegal fishing- In the vicinity of coral reefs, catching live fish for aquariums and seafood markets using cyanide is practised. Despite being contentious, dangerous, and damaging, the practice is nonetheless supported by the wealthy exotic fish industry.

• Pest Control- Coyotes and other canids are killed in the US with M44 cyanide devices. Possums can develop a fear of the bait, but this fear can be diminished by using cyanide pellets. There have been reports of native animals, particularly the endangered kiwi, dying from cyanide poisoning.

Conclusion

It can be concluded that a chemical substance with the 𝐶𝑁− group is referred to as cyanide. The cyano group is created when a carbon atom forms a triple bond with an N atom. Inorganic cyanides contain the cyanide group as the anion 𝐶𝑁−. Both potassium & sodium cyanide is very lethal soluble salts. Frequently referred to as 𝐻𝐶𝑁, the highly flammable liquid hydrocyanic acid is frequently employed in the industry. It is made from cyanide salts that have been acidified.

FAQs

1. What causes cyanide poisoning?

Cytochrome oxidase inhibition, which results in less tissue oxygen uptake, has been proposed as the cause of cyanide poisoning.

2. How dangerous is sodium cyanide?

Sodium cyanide is exceedingly dangerous to humans, just as the very comparable potassium cyanide used in the L-pill. Although there are dangers associated with cutaneous absorption, eating poses the greatest threat. When sodium cyanide is inhaled or consumed, oxygen cannot be transported, which results in major health issues and eventual death.

3. Which cell is more vulnerable to the toxic effects of cyanide?

Cyanide's harmful effects are primarily caused by the termination of aerobic cell metabolism. The ferric ion cytochrome oxidase in the mitochondria forms a reversible bond with cyanide. Preventing the conversion of oxygen to water essentially stops cellular respiration.

4. Does cyanide function as a non-competitive or competitive inhibitor?

More than 40 metalloenzymes react with cyanide, but its fatal effect is non-competitive inhibition of cytochrome 𝐶 oxidase, which prevents cellular respiration & results in hypoxic anoxia.

5. Why is $\mathrm{CN-}$ such a powerful nucleophile?

Since $\mathrm{CN-}$ possesses 2 nucleophilic citations, it is an ambivalent nucleophile. Cyanide is created if carbon receives an electron donation from 𝐶, whereas isocyanide is created if carbon receives an electron donation from 𝑁. Since 𝐶 is less electronegative than 𝑂, it tends to transfer electrons more readily.