Friday, February 17, 2012

The Chemistry of Love

When I was in college I had two things on my mind a lot: dating and chemistry. The reason for the former I assume to be self-evident, and the latter can be simply explained by the fact that I worked as a chemistry TA for my last two years.

That combination of priorities led to an interesting analogy that I often took the opportunity to share. The analogy is what I called "The Chemistry of Love", which I should more accurately call "The Thermochemistry of Love". One person I shared it with was a good friend by the name of Maria Sederberg (because of whom I met Emily for the first time, but that's a story for another day). A while ago, Maria emailed me the following picture, with the request that I re-explain my philosophy on the chemistry of love.
After months of letting it sit in my inbox, I eventually replied as requested, and I include the explanation here for all of you as well.

The aqueous solution represents the dating "pool", and substances in solution are available for reaction. The reaction is for the electron-rich male to find a suitably cationic female with whom to bond and precipitate out of solution, hopefully forming a stable compound. Some males are more more weakly charged than others, and it requires a very strong positive force for the male to notice the positive at all. Others are very highly charged, and nothing but an extremely strong negative presence will repel them from seeking to bind with the cation.

In a process called the DTR reaction, the two soluble ions try to unite. Once they have bound, they first form an aqueous compound that is bonded, but still in solution (dating). If the thermodynamics of the reaction are favorable, the two will eventually form an insoluble solid and the resulting compound will precipitate out of the solution.

Once two substances have met and bonding begins, the ∆G (delta G) of the reaction is what ultimately determines whether the end product is stable. A -∆G (negative delta G) means that the relationship results in beneficial energy being released and creates stable relationships. A +∆G (positive delta G) means that energy is being put into the relationship. As the diagrams demonstrate, this may not be a bad thing.

The diagram on the top left illustrates most successful relationships. They take an initial input of energy, but ultimately gives off more beneficial emotional energy and the reaction has a -∆G. This is good, and contributes to thermodynamic happiness.

The diagram on the top right illustrates that some reactions have only a +∆G, which is bad. The more energy you put into these reactions (relationships), the more energy is released when the compounds have a break up.

The diagram in the middle on the right shows a very dangerous type of relationship. Some reactions may have a stable intermediate, meaning that there is an initial investment of energy and a trend towards a return of investment, but they still ultimately have a +∆G and are unstable. These usually end up as protracted relationships that don't ultimately lead to marriage, and can release a lot of energy when the compounds have a break up.

The last diagram illustrates the thermodynamics of the incredibly rare "love at first sight" reaction.

I admit that it does take some chemistry background to fully appreciate the analogy. However, I don't think it takes any particular expertise to fully appreciate that I can be a real nerd sometimes.


  1. I appreciate and admire the nerdiness and ability to create such an analogy. Thanks for sharing!