Acetophenone (Yum)

I don't have much to say about acetophenone chemically - It is a useful (and very common) synthetic precursor. It's one of a relatively few chemicals that aren't used as a solvent that many labs keep around in liter bottles. The main reason I like it, though, is that it smells wonderful.

Predictably, it is used in perfumery. Like many single chemicals, its smell is puzzlingly hard to pin down (smells, such as coffee, where you definitively say "that's it," are very often mixtures). I'd describe it as something like orange blossom with a bit of artificial cherry/almond.

Acetophenone also is of note for its use in Luca Turin's experiment - a controversial dark-horse theory of olfaction that says vibrational levels (essentially what's given by an infrared absorption spectrum) of a molecule hold predictive power for odorant character. (The mainstream theory says molecular shape is the thing). In one experiment, he found that he could order a perdeuterated acetophenone (exchanging all the hydrogens for an isotope of hydrogen, deuterium). Turin and some others insist they smell different, others insist isotope-exchanged compounds are indistinguishable (see, e.g., here and here.).