So last time we went through all the different trends that affect acidity. The bottom line is that any factor which stabilizes the conjugate base will result in increased acidity. Now it's fine to know trends - it's extremely important, in fact - but what do you do when you want to compare the … [Read more...]
Curved Arrows (for reactions)
If you think of electrons as the currency of chemistry, reactions are transactions of electrons between atoms. Just like double entry book keeping was developed to formalize how financial transactions are recorded, chemists have developed their own convention for showing transactions of electrons … [Read more...]
Evaluating Resonance Forms (1) – The Rule of Least Charges
So far I've talked about resonance, and introduced the curved arrow formalism to show the movement of electrons. Importantly, we've talked about how the "true" picture of a molecule is a hybrid of its resonance forms (and not an equilibrium between forms). Here's a recap of the different "moves" … [Read more...]
Learning New Reactions: How Do The Electrons Move?
The most important question when learning a new reaction is recognizing "What Bonds Form, What Bonds Break?" If that's #1, then what's the second most important question to ask yourself? I think it is: "how do the electrons move?" [I have a friendly disagreement with a lot of instructors … [Read more...]
“Compare Organic Chemistry To A Movie…”
Love this quote, from Organic Chemistry 1 as a Second Language by David R. Klein (fuller review to come) on organic chemistry and memorization. You probably know at least one person who has seen one movie more than five times and can quote every line by heart. How can this person do that? It's … [Read more...]
How (and why) electrons flow
So what is the key "driving force" involved in chemistry? A chemist would say that "opposite charges attract, like charges repel." But how can we make that concept more concrete and specific? I've been going through Daniel Levy's excellent book "Arrow Pushing in Organic Chemistry" (fuller review … [Read more...]
What makes a good leaving group?
A leaving group is a nucleophile acting in reverse; it accepts a lone pair as the bond between it and its neighbor (usually carbon for our purposes) is broken. So what makes a good leaving group? The "happier" and more stable that lone pair is, the better a leaving group it will be. The most … [Read more...]