moleculeoftheday

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Coby

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May 27, 2008
I love stuff like this. A lot of people don't believe that water is blue until they see some really clean water. It really is, though, and the reason is simple yet fascinating. It is because water is blue - very faintly, it's a unique phenomenon because you don't see 10,000 gallon pools of methanol…
May 23, 2008
In the news the last couple days: chloropicrin: Chloropicrin is a pesticide. It's one of the older types that's just generally really, really toxic. It will easily hydrolyze to phosgene and nitrosyl chloride, one of the nasties aqua regia generates. Just recently, a Japanese farmer swallowed some…
May 19, 2008
Mica is neat, you might remember it as the really flaky stuff you used during the minerals demo in grade school: (Public domain wikipedia image) The coolest thing about mica is that it makes a great substrate for AFM. If you take a sheet of mica and put it between two pieces of scotch tape, and…
May 15, 2008
Hexamine is a nitrogenous analogue of adamantane. The coolest thing about it is the exceptionally stable adamantyl-type system assembles on its own if you just mix ammonia and formaldehyde gas. It's got loads of uses, from little fuel tabs for stoves, to a component of explosive mixtures, to…
May 14, 2008
Adamantane is a sort of triple-fused-cyclohexane structure: I've previously covered its role as a functional group in a dermatological drug. The neatest thing about adamantane is that if you make polymers of it, you have carbons with four tetrahedral single bonds to other carbons, or a molecular…
May 9, 2008
Previously I've mentioned triethylammonium acetate, and ammonium carbonate. These are salts formed by mixtures of volatile stuff - triethylamine, acetic acid, ammonia, and carbon dioxide. Awhile ago I made one I hadn't ever made before. This one was triethylammonium bicarbonate, which is weird. You…
May 7, 2008
Triacetin is the glycerol triester of acetic acid: Since it's made of glycerol and acetic acid, it's kinda-sorta-almost edible, and the wiki informs me there is talk of feeding it to spacemen. Aside from its toxicity, it has an great liquid range (3-260C), especially for a nonpolar solvent and it…
May 5, 2008
Automated solid-phase synthesis of biomolecules defines 20th century biology. I previously covered a protecting group that is ubiquitous in DNA synthesis, but the Nobel was actually awarded for peptide chemistry. Fmoc is sort of to amino acids what DMT is to DNA. In amino acid synthesis, you take…
May 1, 2008
Chlorinated solvents are great solvents. The polarizability of chlorine, moderate electronegativity, moderate volatility, lack of acidic protons or reactivity - it all adds up to a great reaction medium. However, they usually are toxic. Carbon tetrachloride, CCl4, used to find a lot of use, even in…
April 28, 2008
Niacin is also known as Vitamin B3. Interestingly, it's also called "nicotinic acid," and the similarity of the name to "nicotine" isn't coincidental: Take a look at nicotine and you'll see the structural similarity. Interestingly, high doses of niacin have been noted to modulate cholesterol (…
April 23, 2008
Is paying $5/liter for Fiji water not cutting it? Trying to come up with a more environmentally abhorrent, gauche hydration accessory? How would you feel about $1,000/liter, along with some iffy health benefits? Gerolsteiner? H2O? What are you, a subprime borrower? The Gulfstream+Carbon Credit set…
April 20, 2008
Oscillating reactions are neat; I should write up one of my favorites sometime... Here, electrons flow from iron metal to mercury (I) sulfate to chromium (VI) oxide. Listen to the video for a step-by step explanation...
April 18, 2008
A couple previous molecules of the day were in the news today: polylactide and lead chromate. I previously covered the use of polylactide in plastic bottles. I also covered a big downside - it's not the sturdiest stuff. Today, Popular Science has a story about its use in plastic bags, which isn't…
April 16, 2008
Phytic acid is an inositol derivative: There was a time when phytate was mostly associated with disease states. All those phosphates make a fine metal binder, and people who lived on plants nigh-exclusively were often short on essential minerals. We eat less plants these days, and phytate has…
April 15, 2008
Inositol is a sugar: Most sugars are aldehydes and ketones, and they zip up into rings in solution on their own, forming rings with oxygens that look like substituted ethers. Inositol is a funny one - an enzyme has to do the work and make a cyclohexane, which won't fall apart without some…
April 10, 2008
As you go down the group, the smells only get worse. You don't smell oxygen (you're soaking in it), sulfur compounds tend to be pretty stinky, selenium compounds are pretty rank, and purportedly, tellurium compounds are the worst. Exposure to even elemental Te can result in your body producing…
April 9, 2008
As far as I know, selenocysteine is the only reason you need selenium in your diet (which you almost certainly get enough of; the requirement is vanishingly small, It is the nucleophilicity that is so important; it is found in the amino acid selenocysteine - that is, the selenium analogue of the…
April 3, 2008
As Uncle Al mentioned, many antioxidants are ill-tolerated by the liver. However, it loves one antioxidant: silibinin. Silibinin, found in Blessed Milk Thistle, is actually hepatoprotective - to the extent that it's used in toxic mushroom poisoning in hospitals in Europe!
April 2, 2008
Benzoyl peroxide is funny. As a commenter mentioned yesterday, it's used in skin care. It's a potent oxidizer (and will quickly do a number on reducing agents like hydroquinone, which is the reason for the warning mentioned). Potent enough that it's an explosive. At 2.5-10% concentration, however,…
April 1, 2008
One of the most heavily trafficked entries on this site is that on TBHQ. While it's an antioxidant, it's a synthetic one, and some have suggested it might be toxic. Another antioxidant, ferulic acid, found in wheat, works on much the same principle and has found less blame. Hydroquinone is, too,…
March 27, 2008
Certain compounds occur as "hydrates"; that is, with one or more molecules of water. Sometimes there is just water trapped in the crystal structure at a specific stoichiometry (i.e., creatine), sometimes the water is actually covalently incorporated into the molecule, as in formaldehyde hydrate.…
March 24, 2008
Happy Dyngus day. Formaldehyde is both a toxic and useful compound. Unfortunately, it's a gas, so it's tough to move around. Typically, you get it as a solution in water - with some methanol to keep it from polymerizing into "paraformaldehyde," which is the other major way to get it. Both are a…
March 20, 2008
As I've discussed in the past, certain dyes can detect radiation, stain DNA, sense solvent polarity, or (in olden times!) color the Chicago River green. This one can make a laser! With sufficiently fluorescent dyes, you can actually take a laser and use it to "pump" a jet of a dye that absorbs the…
March 17, 2008
I posted Sunday and last year about the putative use of fluoresciein in the Chicago river on St. Patrick's day. As some readers pointed out, they apparently aren't using it anymore. I don't even have a guess what they're using, then. The reason the solid dye is orange is because it absorbs blue-…
March 16, 2008
Edit: Looks like I might be off on this. CNN has a clip in the rotation right now about the yearly tradition of dying the Chicago river green for St. Patrick's day. They're saying it's a "secret orange dye." Well, let me put it through the decomplicator for you. As you might remember from last…
March 14, 2008
The readership might also enjoy A Chemical Sabbatical.
March 14, 2008
Like alizarin, indigo is a dye that we used to have to rely on a plant to make. Now we're able to synthesize it: Indigo used to be prepared from natural sources, like plants. Modern synthetic techniques have made it cheap and plentiful. While this might seem like not such a big deal, can you…
March 14, 2008
Wow, sorry. I pretty much missed a whole week there. A consolation Friday entry coming up, but first, if you enjoyed Breaking Bad, you might enjoy Trampled Underfoot, the autobiographical blog of Todd Hall, a chef in the Southwestern US. His career oscillated for years between some dizzying…
March 13, 2008
Flavylium is an unusual heterocycle - it has a trivalent oxygen atom. These tend to be quite reactive - trialkyloxoniums, some of the most potent alkylating agents, contain them. As in the case of tropylium, aromaticity saves the day again. What should be a very unstable compound ends up being…
March 7, 2008
As I mentioned in the previous entries on HF, mercury fulminate, and phosphine, I really like Breaking Bad. As an astute commenter noted yesterday, they sometimes make some mistakes: Like pentavalent carbon (green dots). But they usually do a pretty good job and even sneak in some real chemistry:…