Sciencemadness Discussion Board

Same name different structure ?

DubaiAmateurRocketry - 4-1-2014 at 07:05

I took a screen shot of the lecture paper and the same product on sigma alreich.

I am confused which one is the correct one ?


<img src="http://i40.tinypic.com/2mm65o7.jpg" width="800" />

<!-- bfesser_edit_tag -->[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: reduced image size(s)]

[Edited on 4.1.14 by bfesser]

Nicodem - 4-1-2014 at 07:45

What exactly is your question?
It is perfectly normal that equal structures bear an equal name. What else did you expect?

DubaiAmateurRocketry - 4-1-2014 at 08:05

However the diol groups are placed differently ? I need the compound in the paper for further uses. So how do I know if I shall just buy this or I shall synthesized it my own ? It has same name, same name however different structure.

Pulverulescent - 4-1-2014 at 08:14

Quote:
]However the diol groups are placed differently ?.

Two perspectives ─ one molecule . . .

Nicodem - 4-1-2014 at 08:26

Quote: Originally posted by DubaiAmateurRocketry  
However the diol groups are placed differently ? I need the compound in the paper for further uses. So how do I know if I shall just buy this or I shall synthesized it my own ? It has same name, same name however different structure.

You are not even funny. There is no difference at all. Both structure are completely identical. If you can't read chemical structures, you should not be messing with chemistry.

ScienceHideout - 4-1-2014 at 08:35

DAR- I easily see the source of your confusion. We are always spoiled with those 3d-ish stereo molecules with bonds that jump out at you and stuff, and as soon as something is smooshed down into 2d it is rather confusing-

Here is how to clear it up... It always works for me :)

Build a model of this molecule. I don't care if you use a molecular model set or just a computer simulation like Avogadro. Once you build it, focus on the middle carbon. You will soon see that there is nothing different between these 2 molecules, it is just how you are looking at it :D.

Hope that helps,
SciHide

DubaiAmateurRocketry - 4-1-2014 at 08:37

Quote: Originally posted by Pulverulescent  

Two perspectives ─ one molecule . . .


Ahh right i understood, I thought it was something else. Thank you so much!
Quote: Originally posted by ScienceHideout  
DAR- I easily see the source of your confusion. We are always spoiled with those 3d-ish stereo molecules with bonds that jump out at you and stuff, and as soon as something is smooshed down into 2d it is rather confusing-

Here is how to clear it up... It always works for me :)

Build a model of this molecule. I don't care if you use a molecular model set or just a computer simulation like Avogadro. Once you build it, focus on the middle carbon. You will soon see that there is nothing different between these 2 molecules, it is just how you are looking at it :D.

Hope that helps,
SciHide


Yup I realized, thanks.

and nicodem, sorry for being so stupid, im poor in many parts of chemistry like this one.

[Edited on 4-1-2014 by DubaiAmateurRocketry]

ScienceHideout - 4-1-2014 at 08:57

Quote: Originally posted by DubaiAmateurRocketry  
Quote: Originally posted by Pulverulescent  

Two perspectives ─ one molecule . . .


Ahh right i understood, I thought it was something else. Thank you so much!
Quote: Originally posted by ScienceHideout  
DAR- I easily see the source of your confusion. We are always spoiled with those 3d-ish stereo molecules with bonds that jump out at you and stuff, and as soon as something is smooshed down into 2d it is rather confusing-

Here is how to clear it up... It always works for me :)

Build a model of this molecule. I don't care if you use a molecular model set or just a computer simulation like Avogadro. Once you build it, focus on the middle carbon. You will soon see that there is nothing different between these 2 molecules, it is just how you are looking at it :D.

Hope that helps,
SciHide


Yup I realized, thanks.

and nicodem, sorry for being so stupid, im poor in many parts of chemistry like this one.

[Edited on 4-1-2014 by DubaiAmateurRocketry]


There is a big difference between being unaware and being stupid... You can't fix stupidity! Being unaware is absolutely forgivable in chemistry, and imagining 3d things on flat pieces of paper is something that comes with much practice and experience. I find it really sad that someone would rather insult you and make you believe that you are stupid than help you understand such a topic.

I am glad that you understand this now... and btw- don't call yourself stupid :). Just by studying chem alone you prove you are not stupid :D!

bfesser - 4-1-2014 at 08:58

Those are both terrible drawings, but they do represent the same molecule. The quaternary carbon (the one with three carbons and a nitrogen bonded to it) is not a <a href="http://en.wikipedia.org/wiki/Stereocenter" target="_blank">stereocenter</a> <img src="../scipics/_wiki.png" />, as two of the attached groups (&ndash;CH<sub>2</sub>OH) are identical. It'd be nice to see the molecule represented with solid and dashed wedges, though, or at the very least with decent bond angles.

[edit] What's worse is that the '3D' models that come up with a <a href="https://www.google.com/search?q=2-ethyl-2-nitro-1,3-propanediol&safe=off&source=lnms&tbm=isch&sa=X&ei=Iz7IUsSKA6SI2wWHlYCgAw &ved=0CAkQ_AUoAQ&biw=1317&bih=655" target="_blank">Google search</a> <img src="../scipics/_ext.png" /> represent it as planar! Not even wrong...

<table><tr><td align="center">2-nitro-2-ethylpropane-1,3-diol.png - 2kB</td></tr><tr><td><em>2-nitro-2-ethylpropane-1,3-diol</em></td></tr></table>
I couldn't get the software to cooperate&mdash;first time using it&mdash;but you get the idea.
Quote: Originally posted by ScienceHideout  
. . . imagining 3d things on flat pieces of paper is something that comes with much practice and experience.
Or autism. ;)

[Edited on 4.1.14 by bfesser]

ScienceHideout - 4-1-2014 at 09:14

I attached a better picture that I made using marvin... It is a ball and stick model, I would love for someone to post one with wedges, but I can't figure out how to do that... :P



diol.png - 33kB


LOL- I just now noticed that this completely lacks all hydrogens :)

[Edited on 4-1-2014 by ScienceHideout]