The compound formally known as 1-chloro-3-pentyn-1-yl chloride is now being called ephyn, which is an abbreviation of its chemical name epoxyphyn. The formal name for this chemical is phyenocarbonium ion.
This is an interesting development in the world of chemistry! A new compound is discovered and its name is changed. How often does this happen?
It was only a few years ago that the element nihonium (Nh) was named. Before then, it went by several different names, but scientists came to a unanimous decision on what to call it.
Like with any field, there are always changes and updates. New information is gathered and understood, and sometimes that requires reevaluation of things. This can be seen with the recent discovery of plastibrains—the thin membranes within plants that transport water and nutrients—and their identification as a separate system from the cell nucleus.
Molecular structure
The compound in question is formally named 1,1-chloropenta-3-yne. However, in the scientific community, it is understood that you can replace the “yne” suffix with “ene” when naming compounds.
This is not an official rule, but one that is understood and followed. It makes it easier to know how to name other compounds as well!
The reason this rule is in place is because of how this particular suffix is pronounced. When saying the compound name with the “yne” suffix, it sounds like “one chlorine and three pentanyls.”
By replacing the yne with ene, it sounds like “one chlorine and three pentynes.” This makes it easier to pronounce the compound name.
Functional group chemistry
The name of this compound is a tricky one to figure out. The simplest explanation is that it is named after the carbon chain that makes up most of its structure.
The chloro part of the name comes from chlorine, which replaces two hydrogens in the benzene ring of the cyclopentane structure. The -eno part of pentyne comes from ethyne, which is what replaces one hydrogen in the benzene ring.
The problem lies in how pentyne is spelled. It looks similar to pancy, which is an adjective meaning painful. This is why it may have been mistakenly written as 1-chloro-3-panene earlier in its discovery history.
However, we now know that panyne does not exist, so the correct spelling is pentyne.
Naming alkanes
Alkanes are a group of chemicals consisting of a carbon and hydrogen backbone with a terminal methyl group. They are named by replacing the -ane suffix with -ene and then adding the appropriate terminal methyl group name.
For example, ethane becomes ethylene and methyne becomes methylene. The reason for this is because alkanes are compounds whose molecules contain a backbone of atoms arranged in a certain order that starts and ends with carbon.
The difference between alkanes and cycloalkanes is that the cycloalkanes have a ring shape. This is why they change the -ane suffix to -ene. Alkenes, however, remain the same.
There is no wrong way to name an alkane, but there are ways to check if your name is correct. One way is to see if the compound contains a carbon-hydrogen backbone and if it has a terminal methyl group.
Naming alkenes
Alkenes are molecules that contain carbon–carbon double bonds. These are named by finding the average length of the two terminal carbon atoms, adding a –ene suffix, and then choosing a name that starts with the next letter in the periodic table.
For example, if the two terminal carbons were a carbon and a hydrogen, the molecule would be named ethylene because it is a linear compound containing a ethyl group.
The difference between naming alkynes and alkenes is in the suffix. An alkene ends in –ene, but an acetylene ends in –cyan. This distinction is very important because it can change the chemical property of the compound.
Acetylene is an explosive chemical and it is difficult to purify. Because of this, there are special procedures to handle this chemical to prevent any accidents.
Isomer separation
Isomer separation is the process of separating isomers, or compounds with the same atomic structure but different chemical structures, from each other.
Isomers can be either diastereomers or enantiomers. Diastereomers are molecules with different arrangements of rings in their structure, while enantiomers are molecules that are mirror images of each other.
Isomer separation can be achieved through distillation, chromatography, and fractional crystallization. Each method uses different processes to separate the isomers, and requires different reagents to do so.
For example, in fractional crystallization isomer separation requires first dissolving the compound in a solvent, then filtering out crystals that have different chemical structures on them. Then, you would rinse the remaining liquid with more crystals of the different chemical structure until there are no more left.
Comparing isomers
Isomers are molecules with the same chemical formula but a different structure. There are many types of isomers, including positional and geometric isomers.
Positional isomers differ in the position of a chemical group or atom on the molecule. For example, lactic acid and succinic acid are positional isomers because they have the same number of carbon atoms and hydrogen atoms but differ in structure by the positioning of the carboxylic acid group.
Geometric isomers differ in how many rings the chemical compound has. Butane and 2-butene are geometric isomers because they have different numbers of carbon atoms connected in rings, but they have the same chemical formula: C4H8.
Comparing isomers can be difficult, which is why there are databases dedicated exclusively to identifying individual isomers. These databases use advanced techniques to identify individual molecules, such as using mass spectrometry to identify individual positional and geometric isomer compounds.
Summary
The compound named 1-chloro-3-pentyne is the first chemical produced when cellulose is broken down. This compound is a building block for more complex compounds, and it can be used in industrial applications like plastics manufacturing.
However, this name is incorrect. In 2016, the Compound Naming Committee of the International Union of Pure and Applied Chemistry (IUPAC) decided that the term “chlorine” should no longer be used as an adjective before words that begin with “c.”
According to their official statement, this was done because it was difficult to distinguish between adjectives that began with “c” and those that began with “h.”
The IUPAC decided that all adjectives that begin with “c” should now be preceded by the word “halogen,” instead. This includes compounds like chlorine, chloro-, bromo-, and iodo-.
References
The compound in question is formally named 2-methylprop-2-en-1-ol. However, it is most commonly referred to as methyl methacrylate.
This isn’t a name that was randomly picked. It’s the name of a chemical compound that has been around for quite some time.
In fact, it has been around since the 1800s when it was first synthesized. At that time, it was known as acrylic alcohol. The structure and composition of acrylic alcohol and methyl methacrylate are very similar.
The only difference is that one molecule of hydrogen is replaced with a carbon atom in the structure. This small change makes a huge difference in its properties, though. Acrylic alcohol is solid at room temperature while methyl methacrylate is a liquid.
