Today in lab, I needed a chemical for an experiment I wanted to run. So I ambled to my office where I looked up the chemical in our in house database, and I wrote down the location code for where I might find said chemical ('might' is an operative word when it comes to the reliability of finding a chemical in our inventory). And I ambled to the bin where the chemical was supposed to be residing. Lo and behold! It was there. A 100 gram bottle of nice white crystalline material.
As I was ambling to my bench (I was tired today, so I ambled a lot), I realized that chemical in my hand had a molecular weight of 68.08. That's a pretty low molecular weight (mw) for an organic molecule that exists as a solid at standard temperature and pressure (STP). This got me thinking, "What is the lowest molecular weight pure material that exists as a solid at STP?" But I think that one is a little too easy, so I changed the question, "What is the lowest weight non-ionic organic compound that exists as a solid at STP?" That's a little trickier. I thought maybe it was the compound I had just taken out of the inventory. It's not.
So how do you think about this problem? If you're not a chemist, you don't. You recognize that this is a pointless exercise, and you let it go. But if you're a chemist....not so fast. You're bound to get hung up in a combination of curiosity and knowitall-ism, and you'll spend decidedly too much time thinking about until you have an answer you're satisfied with. You need to think of a molecule that maximizes intermolecular attraction while minimizing molecular weight. Since I eliminated ionic bonding as an option, that means hydrogen bonding. I'd bet good money that water is the lowest molecular weight (a measly 18 atomic mass units) pure substance to exist as a liquid at STP. Why? Hydrogen-bonding, dammit! We'll play the same game to get the lowest mw organic solid. We can maximize hydrogen-bonding by choosing compounds dense in low molecular weight hydrogen bond making heteroatoms (ie. oxygen and nitrogen).
My labmate Jason and I were pretty satisfied that imidazole (the inventory compound) would be the winner, but when I posed the question to another one of our colleagues, Adam, in mere seconds, he outdid us. Urea (mw = 60.06). That bastard out smarty-pantsed us. But Jason doesn't give up that easily. Employing a classic kindergarten maneuver, he changed the rules mid-game. You see, urea doesn't possess a single carbon-hydrogen bond. Can a compound without a carbon-hydrogen bond really be organic? No way! (actual answer: of course!) So we were able to recover our dignity by cheating. Once again, imidazole was the best choice.
UNTIL.... I realized on my drive home that swapping one nitrogen in urea for a carbon and adjusting the hydrogen count appropriately would give us acetamide (mw = 59.07) which saved us one atomic mass unit. Hoo-Ray! Acetamide is also a solid at room temperature. On top of that, it has (count 'em) three carbon-hydrogen bonds. I even found a compound that followed the new rule. I totally win. I emailed my new suggestion to Jason from home. He presumably won't see me message until tomorrow morning. I will rule the night.
...Of course, someone may find a better answer tomorrow. At that point, I will change the rules again.
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