Ring Strain in Cyclopentane and Cyclohexane

April 18, 2014

In the last post, we saw that ring strain of cyclopropane and cyclobutane were 27 and 26 kcal/mol respectively.  They are the unhappiest of rings – constrained into uncomfortable angles, with hydrogens forced by geometry to grumpily line up side-by-side with their repulsive neighbours.  The situation for cyclopentane (ring strain: 6 kcal/mol) and cyclohexane (ring strain: [...]

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Making Music With Mechanisms

April 4, 2014

My friend Harry has an annoying habit. When we’re hanging out, every once in awhile, he’ll put on a serious face and say he has something very important to tell me. Then, when he has my attention, he breaks out that annoying Bryan Adams song that begins with ”Pleeease forgive me…”. He thinks this is hilarious. While it *is* [...]

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Cycloalkanes – Ring Strain In Cyclopropane And Cyclobutane

April 3, 2014

In the last post we saw that cyclopropane and cyclobutane have an unusually high “ring strain” of 27 kcal/mol and 26 kcal/mol respectively.  We determined this by comparing heats of combustion from rings of various sizes, and saw that the ΔHcombustion per CH2 was essentially constant as ring sizes went above 12. Based on these [...]

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Goodwill Notoriously Absent In Miramax, MOC Lawsuit

April 1, 2014

Special to MOC from Variety HOLLYWOOD, CA – Mirimax Entertainment announced today that they are suing educational organic chemistry website Master Organic Chemistry for an undisclosed amount in damages, citing copyright infringement. The issue at stake is the alleged similarity between the brief scene of Matt Damon drawing the molecule ibogamine in the Oscar-winning 1997 [...]

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Cycloalkanes – How To Calculate Ring Strain

March 24, 2014

In the last post we learned about one consequence of the fact that carbon can form rings – that we can form stereoisomers (cis / trans).  This post attempts to explain another very interesting consequence of ring formation. This whole post is about strain.  It all starts with this: it turns out you can learn [...]

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Cycloalkanes – Dashes And Wedges

Cycloalkanes – Dashes And Wedges

March 20, 2014

In the last post, we mentioned that one of the consequences of the fact that carbon can form rings is that small rings (less than 8 carbons) are so rigid that they can’t be turned inside out [video]. One of the important consequences of this, as we’ll see today, is that it leads to the [...]

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Crash Course On Resonance

Crash Course On Resonance

March 13, 2014

One extremely common type of email I get from students goes like this: “I feel way behind on [X] and my exam is coming up in a few days. Do you have any advice?”  Privately, I think: “Sure – do a series of good practice problems on [X], and you’ll be very well prepared.”  But that [...]

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How To Apply Memory Techniques In Learning Organic Chemistry

How To Apply Memory Techniques In Learning Organic Chemistry

March 10, 2014

In the last post we talked about how having a great memory is no guarantee of doing well on many types of organic chemistry exams. As an example I shared the story of one reader, Hussain, who’s developed the ability to memorize an entire deck of cards in just a few minutes, but got a [...]

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How Much Does Having A Great Memory Matter?

How Much Does Having A Great Memory Matter?

February 28, 2014

I recently heard from a reader, Hussain, who told me that he’d been working on memory techniques that allowed him to memorize a deck of 52 cards in just a few minutes. Inspired by this awesome story,  last week I asked my readers how much would it mean to them to have a great memory. [...]

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Introduction to Cycloalkanes (1)

Introduction to Cycloalkanes (1)

February 18, 2014

In the first few weeks of an organic chemistry class, we learn that: Carbon can form up to four single bonds  Carbon with four single bonds adopts a tetrahedral geometry (ideal bond angle: 109.5°) Compared to other atoms on the periodic table, [O, N, S, Si for example] carbon forms very strong bonds with itself [...]

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