this post was submitted on 09 Jun 2025
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Science Memes

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[–] JoShmoe@ani.social 21 points 20 hours ago (7 children)

I’m not smart enough to know this.

[–] FoxyFerengi@startrek.website 16 points 20 hours ago* (last edited 20 hours ago) (1 children)

Some molecules have a rotation that is centered on a chiral carbon atom and is named by the way the other atoms of the molecule rotate. There are some rules to it, but L is levorotatory and means it rotates to the left or counter-clockwise. D is dextrorotatory and spins to the right, or clockwise.

Edit: spelling errors lol

[–] protist@mander.xyz 3 points 20 hours ago (2 children)

These terms can describe any molecule, btw, doesn't have to contain carbon

[–] deranger@sh.itjust.works 3 points 19 hours ago* (last edited 19 hours ago) (1 children)

Not any molecule, it’s gotta be able to have stereoisomers in the first place. There’s no R or S water for example. D/L notation is for biology.

[–] protist@mander.xyz 4 points 18 hours ago (1 children)

Well yes, it does have to have chirality, I just meant it doesn't have to contain any specific elements.

I'm definitely no expert, but isn't the D/L notation used in all of chemistry? Sometimes it's written Δ/Λ, but that's the same thing. Doesn't it just describe a molecule's geometry in a different way from R/S?

[–] deranger@sh.itjust.works 1 points 8 hours ago* (last edited 8 hours ago)

D/L refers to the entire molecule and how it polarizes light whereas R/S looks at every chiral center and has a priority system to assign. I’ve only really seen D/L in biochemistry, regular chemistry is using R/S notation. D/L is the older less precise notation. R/S is much more specific and isn’t related to polarization of light.

[–] FoxyFerengi@startrek.website 3 points 20 hours ago

Fair! I've only taken organic chemistry so far, so that's what I remembered

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