Cyclopropane (C3H6) Structure, Properties, Uses and Risks

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Sherman Hoover
Cyclopropane (C3H6) Structure, Properties, Uses and Risks

The cyclopropane is a cyclic molecule that has the molecular formula C3H6, and consisting of three carbon atoms bonded together in the form of a ring. In chemistry there is a family of saturated hydrocarbons that have a skeleton made up of carbon atoms joined by single bonds in the form of a ring..

This family consists of a varied number of molecules (which differ by the length of their main carbon chain), and are known to have higher melting and boiling points than those of high chains, as well as a greater reactivity than these..

Cyclopropane was discovered in 1881 by an Austrian chemist named August Freund, who was determined to know what was the toxic element in ethylene and who came to think that it was the same cyclopropane.

Even so, it was not until the 1930s that it began to be produced at an industrial level, when they discovered its uses as anesthesia, because before that time they did not find it commercially attractive.

Article index

  • 1 Chemical structure
  • 2 Properties
    • 2.1 Boiling point
    • 2.2 Melting point
    • 2.3 Density
    • 2.4 Reactivity
  • 3 Uses
  • 4 Risks
  • 5 References

Chemical structure

Cyclopropane, of molecular formula C3H6, It consists of three small carbon atoms that join in a configuration such that a ring is formed, leaving a molecular symmetry of D3h on every carbon in the chain.

The structure of this molecule requires that the bond angles that are formed be about 60º, much less than the 109.5º that are observed between sp hybrid atoms.3, which is a more thermodynamically stable angle.

This leads to the ring suffering from a more significant structural stress than other structures of this type, in addition to a natural torsional stress that it possesses due to the eclipsed conformation of its hydrogen atoms..

For this same reason, the bonds that form between the carbon atoms in this molecule are considerably weaker than in common alkanes..

In a peculiar way and unlike other bonds where the proximity between two molecules symbolizes greater bonding energy, the bonds between the carbons of this molecule have a particularity of having a shorter length than the other alkanes (due to their geometry), and at the same time they are weaker than the unions between those.

Furthermore, cyclopropane possesses the stability by cyclic delocalization of the six electrons in the carbon-carbon bonds, being slightly more unstable than cyclobutane and considerably more than cyclohexane..

Properties

Boiling point

Compared to the other more common cycloalkanes, cyclopropane has the lowest boiling point among these types of molecule, voltatilizing at 33 degrees below zero (no other cycloalkanes volatilize at temperatures below zero).

On the other hand, compared to linear propane, cyclopropane has a higher boiling point: it volatilizes at 42 ° C below zero, slightly lower than that of its cycloalkane cousin.

Melting point

The melting point of cyclopropane is lower than that of other cycloalkanes, melting at a temperature of 128 ºC lower than zero. Even so, it is not the only cycloalkane that melts at a temperature below zero, and this phenomenon can also be observed in cyclobutane, cyclopentane and cycloheptane..

So, in the case of linear propane, it melts at a temperature lower than 187 ° C below zero..

Density

Cyclopropane has the highest density among cycloalkanes, being more than two times higher than the densest common cycloalkane (1.879 g / l for cyclopropane, surpassing cyclodecane with 0.871).

A higher density is also observed in cyclopropane than in linear propane. The difference in boiling and melting points between linear alkanes and cycloalkanes is due to higher London forces, which are increased by the ring shape that allows a greater contact area between internal atoms..

Reactivity

The reactivity of the cyclopropane molecule is directly affected by the weakness of its bonds, increasing considerably compared to other cycloalkanes due to the effect of the stress exerted on these bonds..

Thanks to this, cyclopropane can be separated more easily, and can behave as an alkene in certain reactions. In fact, the extreme reactivity of cyclopropane-oxygen mixtures can become an explosion hazard..

Applications

The commercial use of cyclopropane par excellence is as an anesthetic agent, studying this property for the first time in 1929.

Cyclopropane is a powerful, fast-acting anesthetic agent that does not irritate the airways or have a bad odor. It was used for several decades together with oxygen to put patients to sleep during surgery, but unwanted side effects began to be observed, represented as "cyclopropane shock.".

Along with the cost and high flammability factors, it went through a process of discarding and replacing with other safer anesthetic agents..

Although it continued to be part of the compounds used in the induction of anesthesia, today it is not part of the agents used in medical applications.

Risks

- Cyclopropane is a highly flammable gas, which produces toxic gases when it comes into contact with a flame. In addition, it can react with oxidizing agents such as perchlorates, peroxides, permanganates, nitrates and halogens, causing fires and / or explosions..

- High levels of cyclopropane can cause headaches, dizziness, nausea, loss of coordination, feeling faint and / or lightheaded..

- It can also lead to heart rhythm irregularities or arrhythmia, breathing difficulties, coma, and even death..

- The liquefied cyclopropane can cause frostbite on the skin due to its temperature considerably below zero.

- Because it is a gas under ambient conditions, this compound can easily enter the body through the air, and also reduces the level of oxygen in the air..

References

  1. Britannica, E. (s.f.). Cyclopropane. Retrieved from britannica.com
  2. Chemistry, O. (s.f.). Cyclopropane synthesis. Recovered from organic-chemistry.org
  3. ChemSpider. (s.f.). Cyclopropane. Retrieved from chemspider.com
  4. Wagnières, O. (s.f.). Cyclopropane-Containing Natural Products. Recovered from lspn.epfl.ch
  5. Wikipedia. (s.f.). Cyclopropane. Retrieved from en.wikipedia.org

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