Arrows
So in General Chemistry we were introduced to three familiar arrows when we were dealing with observing and studying some reactions, equilibriums and resonance. But just as a quick review lets go over these three arrows again.
Reaction Arrow
This should be a familiar looking arrow because it is just an arr
ow. But in all Chemistry d
isciplines this arrow represents a reaction where reactants are o
n the left and the products are on the right. And at times we might see reagents, solvents, catalyst or even reactants over the arrow. Pretty straight forward and simple, like this arrow itself.
Equilibrium Arrow
This arrow just is a single barbed arrow with the top point to the right and the bottom pointing to the left. This arrow represents reactants and products used in a reaction but does not mean that it favors one side over the other. The reason for this being is easy and logical, it is because the rates on both sides are equal thus theres an equilibrium.
Resonance Arrow
Ok so now that we covered that its time to introduce two new arrows that will be used in Organic Chemistry. These arrows are:Simply put, the resonance arrow represents resonance structures that differ in electron location/configuration and not molecular formula. And thats pretty much it.
Curved Arrows
This arrow is used in mechanisms along with the other arrows shown above. It is important to remember that this arrow never crosses any other arrow just for clarity sake. The arrow is also used to represent movement of electrons and does not represent what happens to an atom.
Retrosynthesis Arrow
This arrow is not used with curved arrow and the reason for this being is that this arrow represents a way to solve how a product is synthesized by placing the reactants on the right and the products on the left.
Resonance
Ok so lets talk about this quickly and briefly since there is not much to talk about as example are much better at explaining this than words. Ok so as I stated earlier resonance is the movement of electrons and electrons ONLY, never atoms. This of course means that the molecular formula must be the same no matter what. So here are a few examples to demonstrate what I am talking about:
Example 1:
Example 2:
Example 3:
Molecular Orbitals and Hybridized Orbitals
Molecular Orbital: Or what I call MO for short are spread across the molecules and give the most accurate picture of electrons but are really hard to visualize, to calculate and to deal with. You might remember these from General Chemistry as well. These were the orbitals that had those funky sigma and pi bond things.
Hybridized Orbitals: These are orbital that give a pretty good picture of whats going on with the electrons on a atom. There are three common ones we should know for Organic Chemistry and they are:
- sp3- which is a tetrahedral shape
- sp2- which is a triangle planar shape
- sp- which is the linear shape
Remember as we go from sp3 to sp the shape goes from being more P like to more S shape. (Oh and incase you forgot a P shape looks like two pears tied together from each others stem and an S shape is just a circle)
Functional Groups
Ok now its time for some fun, now we are getting into some Organic Chemistry here! But lets not get to excited because to tell you the truth this part is just a lot of memorizing and not much else. But we have to do it in order to get what we will study next. So lets get started with JUST 14 now. Yeah sounds like a lot and it is sadly. Ok to save me some time I found a neat figure that gives you 12 out of the 14. All you have to remember is that all we have to know about these groups are how they look like in a atom.
Functional Groups
Missing from Figure:
Nitrile:
Carbonyl:
NOTE: Phenyl is also referred to as aromatic or benzene
Ok so one other things you need to know is that alkyl halides, alcohols and amines have a primary, second and tertiary position. What this means is that each of these can be connected either to one Carbon (primary), two Carbons (secondary) or three Carbons (tertiary). All others do not
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