[DiViNE]

Hello everyone, I am new to this forum (AND to Chemistry). Although I have taken science throughout my Higschool years, I sadly have retained little of that data and have never been shown anything regarding Chemical Diagrams.

I am looking for information, tutorials, or any resources what-so-ever that deal with Chemical Diagrams (Drawing, Understanding, etc...). Just basics really.

I'm talking about diagrams like these especially:
http://ntp.niehs.nih.gov/ntp/htdocs/structures/2d/TR469.gif
a. I'm interested in the particular arrangement of the lines, why they are in these shapes, what do double lines mean, etc...
b. Most notably, i'm assuming the junctions that are un-labelled are CARBON atoms, though why are there those 'inner-lines' parallel to the insides of some of the hexagonal shapes?

Also, information about the more 3D molecular diagrams, such as this one:
http://www.erowid.org/chemicals/harmala/images/archive/harmaline_3d_mid.jpg


Basically, ANYTHING to get me started towards being able to both understand and create such diagrams would be wonderful

I am currently reading an "Intro to Chemistry" site, trying to freshen up my memory, recover past knowledge, and learn more! This is all for personal knowledge, as I have recently had an increasing interest in chemistry (especially stuff like for example: Isolating and Extracting the active ingredients of Ginko Biloba from Ginko Leaves, and then infusing the leaves to make them more potent). Also, anything that you feel would help me in my beginning journey into organic chemistry, and chemistry in general, i'd love to hear about!


All help is appreciated!

Thanks,
DiViNE


P.S. - I'd prefer free knowledge\sites, since i'm in no financial situation to purchase books, however book reccomendations are always welcome [mabye i'll have some extra cash sometime and check em out ]

[Mitch]

If you like chemical structures you'll love this. http://www.chemicalforums.com/index.php?page=molecules

The verticies in the diagrams are carbons the solid lines represent bonds. Double lines mean double bonds, Typically bonds to Hydrogen are not shown unless to highlight stereochemistry or because they feel like it.

[DiViNE]

Thanks Mitch for clarifying the role of the verticies and solid lines.

One thing I do not understand is, for some structures there are hydrogen molecules single-bonded to the carbons. Now, not ALL carbons have this, but alot do. Could you clarify how you know which have these bonds to hydrogen?

Take for example 'tryptamine' in 3D:
http://www.erowid.org/chemicals/other/images/archive/tryptamine_3d_mid.jpg

Now, there it is clearly shown that some of the carbons have hydrogen bonds... though in the 2D model:
http://www.erowid.org/chemicals/images/archive/tryptamine_2d.jpg

These are not shown!


I am confused, is there some special rule\common knowledge that I should be informed about?


Thanks,
DiViNE


P.S. - Downloaded that molecular structure page to conserve bandwidth, thanks

[Mitch]

For 2D representations, usually you simply just want to convey all aspects of a molecule as quickly as possible not wasting any time drawing more than you have to. Thus, if everyone knows that the hydrogens are suppose to be there, you don't have to draw them.

For 3D representations, people are usually interested in how the molecule interacts in real-space and  looks in real-space, thus they include the hydrogens.

In understanding any short-hand in science. The simple rule of thumb is that scientists are lazy and if there is a way to minimize the amount of lines a scientist has to draw/write they will do it. I've seen Chemists use longer abbreviations of words than a shorter version because they have to raise their hand off the page less, and use the shorter version when they type because there is less keystrokes.