Molecules: You'd better learn to live with them.
Pyridine is simply benzene with a nitrogen substituted for one of the CHs:
Such a simple change has myriad effects. The addition of the electronegative nitrogen makes pyridine a good base (it's commonly used in reactions that generate protons to mop up the acid as you go). The same change makes it miscible with water (benzene is only about 0.2% soluble).
Most importantly, however, pyridine stinks. Even at high dilution. It's not a normal piercing chemical scent, either, it has a distinct biological richness that the nitrogenous heterocycles seem to deliver on especially well (witness the intensely fecal indole, for another example). Benzene smells rather pleasantly like gasoline (Both are pretty toxic, by the way), but pyridine smells like an unventilated room full of the infirm and dying.
It's been awhile since we got into stink and I don't want you to walk away thinking this is the worst stuff ever, so expect a few more this week!
Physical Science
Comments
I love me some smelly chemicals. It's what makes working in synthesis labs so much cooler than biology labs.
Posted by: Vince Noir | September 25, 2007 12:17 AM
Vince, I wonder how cool you think this is: Pyridine is known to reduce male fertility!
Posted by: olchemist | September 25, 2007 10:52 AM
Pyridine at high concentrations will fatigue your nose and smell vaguely sweet, ditto H2S. Isonitriles will seize your guts and squeeze hard all the way to your grave. They generally don't make pretty colors with middle and late transition metals, either.
Posted by: Uncle Al | September 25, 2007 2:10 PM
Yah, but, c'mon. It's still fun. And when things smell really bad (ie, pyridine) I try not to inhale a whole butt load.
Posted by: Vince Noir | September 26, 2007 1:41 AM
I recall finding the benzinous smell of gasoline quite pleasant as a child. I am now well on my way to becoming an attorney . . . although I don't think this is causal at all.
Posted by: Adam Engelhart | September 26, 2007 1:45 AM
Oh man that stuff's nasty-smelling. Those two or three of you who are hard-core Mark Leyner fans will recognize the phrase "Lincoln's morning breath" -- that about sums it up.
Posted by: Brian X | September 26, 2007 1:45 AM
olchmist:
The 'ability' of pyridine to reduce male fertility is nothing more than an urban myth. I'd like to see a legitimate reference that accurately describes this...
Posted by: around the corner and down the hall | September 26, 2007 10:11 AM
@the guy down the hall
I want to see the one who volunteers for some accurate tests. In any case the myth is strong enough to be mentioned on safety data sheets and I am not taking the chance ;o)
Posted by: olchemist | September 27, 2007 10:33 AM
Oh man, I was using pyridine the other day and my lab's post-doc walked in, took one sniff, and left. He then called me on my cellphone and told me that he wasn't going to be back until the next day because he couldn't stand the stench.
Posted by: pie.rat | September 28, 2007 7:46 PM
want to see the one who volunteers for some accurate tests. In any case the myth is strong enough to be mentioned on safety data sheets and I am not taking the chance ;o
Posted by: sex shop | December 22, 2007 11:23 AM