Sunday, December 22, 2013

Making nylon

There is something magical about mixing two liquids and pulling out a solid ever-increasing in length. That is to say, ever-increasing until the strand breaks or the reagents run out. There are various strategies for getting the longest possible strand out, this was the first year for the demonstration of the technique below:

The Castleton Chemistree of 2013

Take a stand, clamps, water, food coloring, a modeling kit and fascinating pieces of glassware. Build a chemistree :-)
A really fun activity with a lab full of tired orgo students. And the results are rather cozy.

Check out the reflections on the lab bench!

Thursday, July 18, 2013

Ortho-para and meta directors

It's summer and fruits are amazing this time of the year here. And what to do with chemistry, of course.

So, surprise your friends/family with an ortho-para or a meta substituted benzene ring.

Or perhaps a Rubik's cube fruit salad. Be sure not to cut yourself!

Wednesday, May 1, 2013


A long culminating synthesis experience results in a fun glow for the last organic lab of this spring. The pictures below illustrate the chemiluminescence of Cyalume with a blue fluorescer.

In spite of the successful experiment, the sunny outdoors were still tempting.

Wednesday, April 17, 2013

Making nylon in orgo lab

Below is a picture taken by a current student (Lynn) of the process of nylon-6,6 preparation from adipoyl chloride and hexamethylene diamine. The reaction proceeds in the presence of a base, to improve the nucleophilicity of the amine. The leaving group is the chloride ion.

The reaction resembles the synthesis of proteins in living systems, where tRNA acts as the leaving group after the amine of an amino acid performs the nucleophilic attack.

Friday, March 29, 2013

Catalytic hydrogenation


The current organic chemistry class hydrogenated olive oil using a palladium catalyst. As the reaction begins to come to a boil, the vapor bubbles carry the fine particulate matter of the black catalyst up on their surface. As the bubbles reach the surface, the catalyst falls back.

Sunday, March 3, 2013

Brain Mapping

Organic chemistry introduces a whole new language to students, one which they must learn to speak fluently and apply in practice by the end of their organic class. The subject focuses on the synthesis of various functional groups, as well as their reactivity as reagents. An organic chemist's most frequently pondered question is how to get from compound A to compound B. The courses introduce a set of possible paths. However, the map becomes very complex very quickly.

I encourage any orgo student to make use of a brain mapping software, such as "The Brain" during their time in the course. Start with the very first group of compounds, describe their characteristics, and as you learn their reactions, make the appropriate connections in the software. This way you can visualize the process that a synthetic chemist must think through when designing a new synthesis route for a compound.

Castleton presents the 2012 fall installment of the classes "organic brain" with the following login information on the brain website:
ID: Castetonbrain
Password: GoCState

Click the pdf filed for synthesis routes. Enjoy and give the students feedback here!