100 Nano-Stories: How Do We Name Cycloalkanes?
Episode #29: Cycloalkanes Explained!
Preface! → ✨
It’s your favorite material science & nanotechnology enthusiast reporting back for another article! In the last article, I talked about the importance of alkanes to understand aerogels and their structure! I would highly recommend you take a quick read over that article to understand the next concepts! Don’t worry, it’s a 4-minute read! 😉
But for today’s topic, we will be discussing how to name cyclo-alkanes without guessing or looking up the answers, reader!
Are you sure, Carlos? Even if you explain it easily, I can still Google up your article and use that to cheat -er, I mean help me with my homework! 😁
Naming Of Cycloalkanes Explained! 😤
Fundamental Concepts! 🔑
An alkane is an organic compound that is only made out of carbon & hydrogen atoms, only single covalent bonds.
A single bond means there are only two electrons (or one pair) being shared between two atoms.
A cyclo-alkane means the carbon atoms are connected in the form of a ring, and the carbon bonds are single-bonded to other atoms.
Before you continue, reader, make sure to grasp these 3 concepts, or it will be tough to follow along with us as we break down on naming cyclo-alkanes!
Hey, Carlos, but can you do us a favor while you’re explaining how to name a cycloalkane?
Examples & Breakdown! 🔑
The 1st photo, or cyclo-propane, is 3 carbons attached to form a “ring” around each other. We use the suffix “propane” when we have 3 carbons attached.
The 2nd photo, or cyclo-pentane, is 5 carbons attached to form a “ring” around each other. We use the suffix “pentane” when we have 5 carbons attached.
The 3rd photo, or methyl cyclohexane, is a smidge more complicated. The suffix “hexane” is used when we have 6 carbons attached. But do you notice that line attached to the carbon ring (cyclohexane)?
This is a methane group! “Methane” is used when we only have one carbon atom attached. But because it is attached to cycloalkane, we will have to use the suffix “yl”. So “Methane” becomes “Methyl” in our cyclo-alkane!
We add “methyl” in the front of the suffix “cyclohexane” because it is separate from the main carbon ring, and because no other groups are ending with the suffix “yl”.
Well, that’s interesting, Carlos! But this was easy! Give me something harder! 😤
The Final Boss! 🔑
Here we go, reader! You asked for it, so we’re solving it!
If we notice the main carbon ring, it has 6 carbon atoms (or sides), and because it is single-bonded, that makes the main carbon ring cyclo-hexane.
But we notice that there are other carbon bonds, attached to the cyclo-hexane. Our goal is to count from each attached carbon bond and count clockwise to reach all of the carbon bonds in the shortest amount of counts. Thankfully, the clockwise counting has been done for us!
The bonds that contain “CH3” has one carbon attached, and because it is attached to the main carbon ring, it’s a “methyl”. But because two bonds only have one carbon attached, we attached the prefix “di”. The final product is the term “di-methyl”!
The bond that contains “CH2 CH3” has two carbons attached, and because it is attached to the main carbon ring, it’s an “ethyl”.
Thanks for the technical names, but how will we name this organic compound?
Remember our terms “cyclo-hexane”, “ethyl”, and “di-methyl”?We name the organic compound based on the alphabetical order of the suffix terms of the attached carbon atoms only (anything that has “yl” in its name)! Ethyl comes first, then di-methyl, and finally, the main carbon ring, cyclo-hexane!
And last but not least, the numbers! Because the ethyl group is located on carbon atom number 2, we start with “2 - ethyl”. Next, we have the di-methyl groups. Since they are located on carbon atom numbers 1 & 4, we name the methyl groups as “1,4 - di-methyl”. And finally, the main carbon ring, “cyclo-hexane”!
Here is the final answer to the problem: 2- ethyl - 1,4 di-methyl cyclo-hexane!
Closing Thoughts! → 💭
So, how are all of my readers figuring out how to name cycloalkanes for our future aerogel articles?
Hmmm. . . I see, maybe that was a bit too much! 😅
Tell you what, I’ll make another article which explains the prefixes & suffixes of alkanes, along with how to count the carbon atoms properly! 😁
But for now, let’s try and fix that skull of yours from all that information. . .
Vocabulary! → 📓
“yl”/moieties → A substituent, or chemically bonded parts of molecules attached to a larger backbone/ring.
Alkane → An organic compound that is only made out of carbon & hydrogen atoms, only single covalent bonds.
Single-bond → There are only two electrons (or one pair) being shared between two atoms.
Cyclo-alkane → The carbon atoms are connected in the form of a ring, and the carbon bonds are single-bonded to other atoms.
C → Carbon Atom.
H → Hydrogen Atom.
Ethyl → Two carbon atoms are attached to the backbone/ring of a cyclo-alkane.
Methyl → One carbon atom is attached to the backbone/ring of a cyclo-alkane.
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© 2021 by Carlos Manuel Jarquin Sanchez. All Rights Reserved.
