Organochlorine chemistry

Some things have a special bond.

This bond uses carbon and chlorine. These things are used in many ways. They can be used to clean oil. They can also make plastic.

Some can even be used as medicine. But some can be bad for the Earth. They can stay in the air and water. They can also hurt birds. We must use them with care. Do you see these things around you?

Organochlorine chemistry is the study of special molecules. These molecules have a bond between carbon and chlorine.

Scientists use these parts to make many things.

Some are used as solvents. A solvent is a liquid that can dissolve other things. These are good for cleaning grease and oil. They do not catch fire easily. Other organochlorides help make plastic. One big type is called vinyl chloride.

Most of it becomes PVC plastic.

These chemicals can also be found in nature. Some come from bacteria or volcanoes. Forest fires can also make them. Some are even found in tree frogs. One type of chemical from a frog can help stop pain. This helps scientists study new medicines.

However, some organochlorides can be bad. They can hurt the environment. For example, a chemical called DDT was used on bugs. It can stay in the food chain for a long time. It also caused bird eggs to become very thin. Some of these chemicals are even used as weapons. But not all are bad. Some are safe to eat, like the sweetener sucralose. Many medicines also use these bonds to work.

Organochlorine chemistry is the study of special molecules called organochlorides. These are organic compounds that have a bond between a carbon atom and a chlorine atom.

Because these bonds change how a molecule behaves, there is a huge variety of them. They can have many different names and uses in our world. Some are helpful for making products, while others cause big problems for nature. Understanding these molecules helps scientists learn how to build new things or protect the Earth.

Adding chlorine to a hydrocarbon changes how the substance works. For example, these molecules are usually denser than water. This happens because chlorine atoms are heavier than hydrogen atoms. They also tend to have higher melting and boiling points. Adding more chlorine also makes the substance less likely to catch on fire. Some of these molecules can even act as alkylating agents. This means they can cause damage to living cells.

Many of these compounds are found in nature rather than being made in a lab. They can come from bacteria, volcanoes, or even forest fires.

Some are even found in tree frogs. These frogs get a chemical called epibatidine from the things they eat. This chemical can help stop pain, which is very interesting for medicine research. However, it was not used for patients because it was not safe enough. Other chlorinated bits are found in seaweed and many types of living things.

Scientists use different ways to prepare these chemicals in a lab. They might use UV light to add chlorine to certain molecules. They can also use a reaction called the haloform reaction. This method used to be used to make chloroform.

In big factories, they use ethylene and hydrogen chloride to make chloroethane. Another way is called oxychlorination, which uses oxygen instead of pure chlorine. This can be a way to save money during production.

We use organochlorides in many parts of daily life. The biggest use is making vinyl chloride, which becomes PVC plastic.

Many liquid organochlorides are used as solvents for cleaning grease or dry cleaning. Some, like DDT, were used as pesticides to control insects. However, DDT was bad because it stayed in the food chain and made bird eggshells thin. Not all are bad, though. Some are safe to eat, like the sweetener sucralose, and many medicines use them too.

Organochlorine chemistry is the study of organochlorides. These are organic compounds containing one or more carbon–chlorine bonds.

This field is essential because these molecules have very different properties. Their structural variety leads to a wide range of names and uses. Some organochlorides are helpful in industry, while others cause environmental harm. Understanding these bonds helps scientists manage everything from plastics to medicines.

Adding chlorine to a hydrocarbon changes its physical and chemical behavior. Chlorine atoms have a higher atomic weight than hydrogen atoms. Because of this, organochlorides are typically denser than water. They also possess higher boiling and melting points than similar hydrocarbons. Increasing the amount of chlorine substitution reduces a molecule's flammability. Some aliphatic organochlorides act as alkylating agents. This occurs because chlorine can act as a leaving group. This process can result in damage to living cells.

Many organochlorine compounds occur naturally in the environment. They are found in bacteria, macroalgae, and even humans. Chlorinated organic compounds exist in many biomolecules like amino acids and steroids. Some, like dichloromethane and chloroform, are isolated from seaweed. Natural chloromethane is produced by volcanoes, forest fires, and microbes. Dioxins are also produced naturally in high-temperature forest fires. These can be found in the ashes of lightning-ignited fires.

Scientists use several methods to prepare these compounds in laboratories. Alkanes can be chlorinated using UV light under free radical conditions. However, controlling the extent of this chlorination is difficult. Aryl chlorides may be prepared via the Friedel–Crafts reaction using a Lewis acid catalyst. The haloform reaction uses chlorine and sodium hydroxide to create alkyl halides. This method was formerly used to produce chloroform.

In industrial settings, ethylene reacts with hydrogen chloride to create chloroethane. Oxychlorination is another method that uses oxygen to save costs.

Organochlorides serve many critical roles in modern industry. The largest application is the production of vinyl chloride. In 1985, annual production reached approximately 13 million tons. Most of this was converted into polyvinylchloride, or PVC. Many low molecular weight organochlorides serve as chlorinated solvents. These include dichloromethane, chloroform, and tetrachloroethylene. They are useful for degreasing and dry cleaning because they dissolve oils. They are also effective because they are relatively non-polar and do not mix with water.

Some organochlorides are used as pesticides to control insect populations. DDT-type compounds work on the peripheral nervous system. They prevent the closure of sodium channels in the axon. This causes sodium ions to leak through the nerve membrane. This leakage creates a destabilizing negative "afterpotential" that causes nerve hyperexcitability. Other pesticides, like chlorinated cyclodienes, target the central nervous system. They bind to the GABA-gated chloride channel to inhibit chloride flow. This can lead to tremors and seizures in insects.

While some organochlorides are toxic, many are safe or even beneficial. Dioxins and DDT are persistent pollutants that pose environmental dangers. DDT can accumulate in food chains and cause eggshell thinning in birds. However, the presence of a carbon-chlorine bond does not always mean toxicity. The artificial sweetener sucralose is a common food additive. Furthermore, over 165 organochlorides have been approved for use as pharmaceutical drugs. This includes the antibiotic vancomycin and the antidepressant sertraline. Natural compounds like epibatidine from tree frogs have even stimulated research into new pain medications.