John Carlos Baez on Nostr: Students who *memorize* organic chemistry consider it torture. But to *explore* is a ...
Students who *memorize* organic chemistry consider it torture. But to *explore* is a delight. It's like the difference between being force-fed and grazing at a buffet.
For example, yesterday I learned about 'crown ethers' - beautiful crown-shaped molecules of carbon, hydrogen and oxygen.
Here is a ball-and-stick model of one called 15-crown-5.
Why is it called that? I guess because it has 5 oxygens (in red) and 10 carbons (in black) for a total of 15 heavier atoms. Then there are a bunch of hydrogens poking out. It has perfect 5-fold symmetry.
One use of crown ethers is to hold metal ions. A sodium atom with one electron missing can snugly fit inside 15-crown-5. So can a transition metal with two electrons missing, like cobalt (Co²⁺), nickel (Ni²⁺), copper (Cu²⁺), or zinc (Zn²⁺) . Other metal ions fit better in other crown ethers. I'll show you how it works...
https://en.wikipedia.org/wiki/Crown_etherhttps://en.wikipedia.org/wiki/15-Crown-5(1/n)
Published at
2025-10-04 09:04:41 UTCEvent JSON
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"content": "Students who *memorize* organic chemistry consider it torture. But to *explore* is a delight. It's like the difference between being force-fed and grazing at a buffet.\n\nFor example, yesterday I learned about 'crown ethers' - beautiful crown-shaped molecules of carbon, hydrogen and oxygen. \n\nHere is a ball-and-stick model of one called 15-crown-5. \n\nWhy is it called that? I guess because it has 5 oxygens (in red) and 10 carbons (in black) for a total of 15 heavier atoms. Then there are a bunch of hydrogens poking out. It has perfect 5-fold symmetry.\n\nOne use of crown ethers is to hold metal ions. A sodium atom with one electron missing can snugly fit inside 15-crown-5. So can a transition metal with two electrons missing, like cobalt (Co²⁺), nickel (Ni²⁺), copper (Cu²⁺), or zinc (Zn²⁺) . Other metal ions fit better in other crown ethers. I'll show you how it works...\n\nhttps://en.wikipedia.org/wiki/Crown_ether\nhttps://en.wikipedia.org/wiki/15-Crown-5\n\n(1/n)\nhttps://media.mathstodon.xyz/media_attachments/files/115/315/001/748/962/832/original/f2d5f9883ba4e77c.png\n",
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