So, now that we know how to interpret shortened dot structures. I think I shall go into a bit of the functional groups.
A functional group is a group of atoms/bonds that possess a predictable chemical behaviour.
I will cover some of the most common functional groups that I know. If I've missed any, feel free to comment those.
First of all, I will put them into three categories.
1. Carbon with multiple bonds.
We call this an alkene. Usually those R groups will be just a few hydrogens and carbons. But it can be anything...
We call this an alkyne. Also, keep in mind that carbons can only have four bonds. Well actually they could have more but that's a different topic altogether.
Lastly, we have this called an aromatic ring or arene, even though you may think it is an alkene, it is not.
2. Carbons bonded to electronegative atoms.
Firstly, there is carbon/carbon groups/R groups bonded to a nitrogen atom. We call this amine, and amine due to the presence of nitrogen.
Second of all, R groups bonded to an oxygen which is bonded to a hydrogen \(\rightarrow\) a hydroxide group. This is called an alcohol.
Now, if the oxygen is bonded to some R group, it is called an ether.
Alright, how about I replace the oxygen in the alcohol with sulfur? Sulfur is on the same group as oxygen. So I can do that. We call this a thiol.
Of course, now I can replace the oxygen in the ether with sulfur as well. This is called a sulfide, or a sulfide group.
Now, let's have an R group bonded with a halogen (Side note: halogens are the elements on group 17). This kind of compound is called an alkyl halide.
3. Carbon double bond with oxygen.
This is generally called the carbonyl group.
Firstly, if I have a carbon bonded* with a R group and a hydrogen and double bonded with an oxygen. This is called an aldehyde. The word aldehyde comes from alcohol dehydrogenatum meaning, alcohol deprived of hydrogen.
Now, let's replace the hydrogen from the aldehyde to a R group. We get what is known as a ketone.
So, let's keep going. Let us now replace the R group with a nitrogen attached straight to it. This is labelled as an amide.
Main difference between amine and amide is that amide is right next to a carbonyl group, if there wasn't that carbonyl group then, it would be an amine.
Hmm, I'm running out of ideas... Let's replace the nitrogen with a hydroxide group. We get... a carboxylic acid.
Now a R group without the hydrogen is called an ester.
Right, now let's replace the R group with another carbonyl group. This is labelled as an anhydride.
I know this is getting boring now, but bare with me.
Finally!! Let's put a halogen next to a carbonyl!!
And we get an acyl halide.
There are more but these, in my mind are some of the most common types.
Haha, hopefully, that was useful. ^^ A bit long, I guess. :P