Chemical Equation for Syphilis

June 10, 2006 2:04 PM

I found this chemical equation on the wall of a men's room in a bar last night. What is it? More importantly, why would someone write it above a urinal at a bar?
posted by nomad to science & nature (15 comments total)

4-methyl-sept-2-ene
posted by matthewr at 2:09 PM on June 10, 2006

I don't think there's any significance to it - probably just a doodle by a bored chemist.
posted by pombe at 2:10 PM on June 10, 2006

Not a very competent chemist, evidently - the carbon that's bonded to three other carbons should only have one hydrogen attached (i.e. CH not CH₂).
posted by matthewr at 2:17 PM on June 10, 2006

assuming he's incompetent, can anyone guess what his/her intent might have been?
posted by nomad at 2:21 PM on June 10, 2006

It could be an oblique prank. There's a compound called hexamethylenetetramine that's a byproduct of the urinary tract; it's a key ingredient in manufacturing rubber, in addition to high-melting explosives (HMX).

A shipment of the substance had been reported by the New York Times as having been stolen looted following the fall of Saddam Hussein's regime. So in a certain sense, you could get away with saying you found WMDs in the little boys' room.
posted by Smart Dalek at 2:36 PM on June 10, 2006

It's not far off from valproic acid, which is an anticonvulsant, but I doubt that's what they were thinking.

Most likely it was a chemist or chemistry student trying to think of an intermediate for their latest synthesis, or else just someone doodling around enigmatically while waiting for nature to take its course.
posted by ikkyu2 at 2:43 PM on June 10, 2006

I don't understand, Smart Dalek. How is hexamethylenetetramine related to the compound in the picture?
posted by matthewr at 2:48 PM on June 10, 2006

Actually, I'm wrong about the "4-methyl-sept-2-ene" bit - the correct prefix for 7 is 'hept-', so it would be "4-methyl-hept-2-ene".
posted by matthewr at 2:53 PM on June 10, 2006

More to the point.... how does one write and pee simultaneously? If not simultaneously, then did the perp write it before or after the urination?

Is it anticipatory chemistry or observation?

I'd be looking for a chemical notation for trouser tracks if I tried to be an efficient graphic artist and successful eliminator.

The range of human endeavor never fails to amaze me.
posted by FauxScot at 3:20 PM on June 10, 2006

As an aside, is there a site that explains how one can figure the "4-methyl-hept-2-ene" bit? I find chemistry interesting and would like to learn more about that kind of notation. This actually ties directly into the question, too.
posted by chef_boyardee at 3:37 PM on June 10, 2006

Yea, it's pretty much not an interesting compound at all. I would guess someone who's in Orgo 101 at a nearby college doodling?
posted by raf at 3:44 PM on June 10, 2006

chef_boyardee writes "As an aside, is there a site that explains how one can figure the '4-methyl-hept-2-ene' bit?"

It's called "IUPAC nomenclature" (international union of pure and applied chemistry, thanks for asking), and you can find the complete rules here. Any introductory organic chemistry book will give you a good introduction, and, as might be expected, Wikipedia has a good general introduction as well. Wikipedia really excels at this sort of thing, I find.

Note that for a great many chemicals, there's a conventional name that most working chemists use and that differs from the IUPAC name. The IUPAC system is a completely formalized and comprehensive system: so systematic that computer programs can generate the proper IUPAC names of chemicals. These names are often too unwieldy for common usage, however.
posted by mr_roboto at 4:01 PM on June 10, 2006

I was taught it at school, so I don't know of any online resources, chef_boyardee. Google suggested this Wikipedia page, which has a bit about naming alkanes.

(But most Wikipedia pages about this sort of thing veer wildly between oversimplification and "science penis" contests).

The name for this kind of chemical naming is IUPAC nomenclature.

Basically, the way you'd name the thing in the picture is:

Work out what kind of chemical it is. This is a hydrocarbon with a carbon double bond in it (the CH=CH bit). Therefore it is an alkene - you just have to remember these definitions, there's not really any way to work them out. This gives you the ene bit. The C=C double bond is called the functional group - it's what distinguishes alkenes from other hydrocarbons and gives them their distinctive properties.

Find the longest chain of carbons that contains the functional group. The longest chain is 7 carbons long - starting at the left, moving right and then down the vertical chain. The prefix for 7 is hept.

The -2- part tells you where the functional group is in the structure. Starting at the end of the compound nearest to the C=C bond, i.e. the left, count along the carbons until you get to a carbon which is in the double bond. In this case, the second carbon is double bonded (to the third), so we call this hept-2-ene.

Look for any leftover bits. There's a CH₃ bonded to the fourth carbon atom (still counting from the left). CH₃ is called a methyl group. The prefix 4- is used to show which carbon the methyl group is bonded to.

End result: 4-methyl hept-2-ene
Phew!
posted by matthewr at 4:06 PM on June 10, 2006 [1 favorite]

On preview, mr_roboto's Wikipedia page is actually really good.
posted by matthewr at 4:09 PM on June 10, 2006

And, yeah, I don't think it's an interesting chemical. Probably a doodle by an intro student, as the mistake matthewr points out is a pretty basic one. A real chemist would notice a chiral center, and get the number of hydrogen atoms on it right.

Unless.... the branch was added later, and what you're looking at was originally pent-2-ene (or 2-pentene, if we choose to ignore that bit of IUPAC awkwardness).
posted by mr_roboto at 4:12 PM on June 10, 2006