How to draw 3D structural formula

Hey. I am unsure how to draw 3d strcutural forumla from 2d structures. Does anyone have any tips? Thnx

w00t Exalted member

Reply 1

charco

Study Forum Helper

try to imagine the molecule lying with its main skeleton on the 2D surface of the paper and any bonds that go behind the paper draw as dotted lines, any bonds that stick out from the paper draw as triangles starting with the apex at the molecule paper surface and getting slightly bigger towards the attachment.

Start with simple molecules like methane and work up to cyclic molecules like cyclohexane.

have a look at the attached gif

methane.gif1.9KB

Reply 2

Library

Does the dotted line always go next to the thick triangular line?

Reply 3

Library

For example, what would this structure look like andw why? (strucutre in attachment)

Thanks guys :smile:

help!

Library

Does the dotted line always go next to the thick triangular line?

That is the accepted method as that is actually how it would look.

The best way to learn what molecules will look like in 3D is to use a model kit. www.cochranes.co.uk have a number of kits available and if you are planning on studying Chemistry further then the £12 or so is well worth it.

Reply 6

markkey

Ok, I have done my best here to try and work out what the 3D structure may look like. This is where I wish that I had a model kit handy.

The only problem with giving definate answers is that each of the single bonds in the molecule can rotate and so there are and infinite number of ways the rotation could take place in the overall molecule. I think I have produced the lowest energy conformation here but it is quite a large molecule to work with.

Also there are 2 possible structures due to the chiral centre on the C containing the carboxylic acid, hydeogen, amine and methyl benzene. I have drawn the mirror image as well so both are covered.

Charco do you agree with these structures (just for a second opinion)?

3d structure.JPG9.8KB

Reply 7

charco

Study Forum Helper

yes, pretty much (although you've missed out one of the hydrogens at the chiral centre) - you're point about rotation is important and makes the actual 3D structure rather irrelevant, the most important features being the relationship of atoms to one another.