Iodoform (Wet tests and sterile gauze)

Another theme week: Iodine.

Iodoform is, as the name suggests, the iodine analogue to chloroform.

Iodoform: InChI=1/CHI3/c2-1(3)4/h1H

Iodoform, as the Wikipedia entry mentions, isn't the best antiseptic in the world, but they're mistaken in saying it's not used anymore: iodoform impregnated gauze is still found in hospitals.

Another notable application of iodoform, also antiquated, is the iodoform reaction. This is one of a number of "wet tests" that were once used to characterize compounds. Before spectroscopic techniques became as robust as they are now, they had a place in the lab. Now, two groups of people bother reading about them - conniseurs of old-timey science (guilty) and college sophomores taking organic chemistry lab.

One rite of passage in organic laboratory is the "unknown lab" (which is still ubiquitous as far as I know). Traditionally, you were given a sheet of tests as in the above link, a vial full of some powder or liquid, and set loose in the lab. By performing the tests (and measuring the melting/boiling temperatures of your compound), you (hopefully) could sort out what you had.

In practice, these wet tests are deemphasized in favor of teaching something more useful - usually NMR. The mix varies, but most labs haven't given the old-timey tests up completely.

Tags

More like this

There is lots of organic fun to be had with heavy halogens! Tetrakis(4-halophenyl)methanes (Br, I) crystallize with sets of four halogens clustered. Curiously, tetraphenyl methane plus CX4 1:1 co-crystallize to give essentially the same structure. Hexamethylenetetramine is another tetrahedral donor to tetrahedral covalent heavy halogen.

http://pubs.acs.org/cgi-bin/abstract.cgi/jacsat/1996/118/i17/abs/ja9533…

(Hold your nose.) Uncle Al says, "The loose packing and large polarizabilities of these molecular scaffolds promise new hydrogen storage modalities for consumer transportation needs." (Resume normal breathing.)

Why wasn�t this posted a month ago?
there was a question about iodoform in a chemistry olympiad I took and I did�t know what it identified.
It was still an evil question anyway as the test was for highschoolers...