Molecule of the Day

Potassium Chlorate (Explosive or harmless oxygen generator?)

Wed, 27 Aug 2008 23:10:53 -0500

Potassium chlorate, KClO₃, is quite oxygen-dense and a potent oxidant. It is used in what we called "whippersnappers" and the suppliers called "Pop-Pops" as kids, along with silver fulminate. There is a singular irony in that the wimpiest firework, the one we could buy even in my solidly blue no-fireworks mommy state, contains two components of some dangerous explosives. But we're talking micro- to milligrams, so don't get any ideas.

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Sarin (Nasty.)

Mon, 25 Aug 2008 22:46:03 -0500

Sarin is an organophosphate that irreversibly inhibits cholinesterase. it's a neurotoxin, and a potent one. It'd be absolutely terrifying as a weapon, if it weren't so unstable. Even if a rogue state had gobs of Sarin last year, it's all pretty much a dud by now. The instability of acid halides (carbonyls there, but all of them in general) pretty much ensures this. So the civilized world has that going for it, which is nice.

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Hexanoic Acid (Goats, and Remember Tenderbutton?)

Thu, 21 Aug 2008 23:23:06 -0500

Short alkanoic acids stink. Apparently hexanoic acid smells of goats:

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Sodium borohydride (Medium reducing)

Tue, 19 Aug 2008 21:40:55 -0500

Sodium borohydride is intermediate to the jackhammer that is LAH and the pussycat that is cyanoborohydride.

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Perchloroethylene (Oddly ubiqutious)

Wed, 13 Aug 2008 23:11:54 -0500

Trying to think of a molecule tonight, my friend suggested "pick an ugly one no one wants anymore...a clearance rack molecule." I immediately went to chlorinated solvents. They're in the backwater now, right? Carbon tetrachloride sure has a bad rep. I figured most of the organochlorides, except for the ubiquitous lab solvents, would, too. I was wrong.

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Pyrene (Photo-neat)

Mon, 11 Aug 2008 22:37:14 -0500

Pyrene is a simple, four-fused benzene PAH:

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Dewy Propionate (Funny functional group names)

Thu, 07 Aug 2008 20:26:40 -0500

I love reading lists of fragrance chemicals. The assignment of pleasant, qualitative fragrance descriptions to chemicals with hard-nosed, rigorous functional group names always makes me giggle a little. Acetophenone, for instance, smells of orange blossoms. Today, I came across one that has both in the name: dewy propionate:

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Vote and help kids...

Tue, 05 Aug 2008 09:00:00 -0500

If you have been reading SB long enough to remember the DonorsChoose promotion, you might be interested in this. It's videos of scientists talking about their first experiments and why they like science, and if you vote on the one you like best, DC gets a buck. Check it out here.

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Erythorbic Acid (President Bush have a less-carcinogenic hotdog with me)

Mon, 04 Aug 2008 20:01:56 -0500

Erythorbic acid is a common food additive:

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Nardil/Phenelzine (Hydrazine chases the blues away)

Tue, 29 Jul 2008 07:51:17 -0500

As I mentioned yesterday, derivatives of arylethylamines - phenethylamine in particular - are drug targets in depression, but a sophisticated mechanistic understanding remains elusive. When you have some idea what molecule you'd like less of, a favorite trick is to find something (an "inhibitor") that binds to some enzyme in the pathway to your molecule and mucks up the works.

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Reserpine (Depressing antihypertension medication)

Mon, 28 Jul 2008 01:14:16 -0500

An aromatic ring, two carbons, and a nitrogen will get you a lot of places.From hallucinogens to decongestants to speed, the arylethylamine moiety works because it tickles neurotransmitter receptors. The effects of the assorted monoamine neurotransmitters are as varied as those of the drugs that mimic it - hypertensive, euphoriant, the works. This is part of how we try to explain to ourselves how antidepressants that block the breakdown of these neurotransmitters (MAO inhibitors) or their reuptake (SSRIs) might be working. What might happen if you took something that depleted some of those monoamine neurotransmitters?

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Choline Chloride (Vitamin or solvent?)

Thu, 24 Jul 2008 23:58:49 -0500

Choline is an ubiquitous vitamin. Interestingly, it makes a number of "deep-melting eutectics" with other dirt-common chemicals like Urea.

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Dimethylaminopyridine/DMAP (Nucleophile magic)

Wed, 23 Jul 2008 00:22:10 -0500

A lot of reactions with nucleophiles' rates are determined by how good a leaving group you have. For leaving group reasons and others, DMAP is a great organocatalyst:

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Sulfur Dioxide (Alternative, more toxic refrigerants)

Fri, 18 Jul 2008 23:09:57 -0500

As was mentioned in the comments to my entry on a refrigerant Monday, what we use has changed quite a bit over the years. If you don't know how a fridge or AC works (they're the exact same thing), here's what happens: know how evaporation something makes things cooler (e.g., sweat?). Condensing something makes things hotter by the same principle. Refrigeration involves evaporating something and using the cold for what you want, then moving the vapor somewhere and compressing it (turning it into hot liquid) and dumping that heat somewhere else. Then you evaporate it again and get some more of that sweet cold stuff. And on and on it goes.

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Iodotrifluoromethane (Safer because it's more reactive?)

Mon, 14 Jul 2008 23:09:58 -0500

I really, really love refrigeration. I will go so far as to say that it's the most important invention of the modern era. More than internal combustion, nuclear bombs and power, or electrification, refrigeration defines the US. If you're like most Americans, you preside over at least THREE refrigeration units - one in the house, one in the kitchen, one in the car. The Central Valley in CA, DC, Las Vegas, Phoenix, Dallas, Houston, Atlanta - a huge swath of the country would look very different without AC. Not to mention your grocery store.

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