Re: IR & carbon-Halide

In article
<<pq9me.1657$s64.580@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>,> John Doe
III (john_doeIII@xxxxxxxxx) says...
> Ok, I just read somewhere that IR spectroscopy doesn't help determine
> carbon-halide but helps determine carbon-single bond-hydrogen. Is it true? I
> am a little skeptical about the carbon-halide part. Thanks so much in
> advance.

Well, it depends what IR active mode you're talking about, of
course, but a simple C-X stretch is typically around 2950 cm^-1
(for an alkane), compared to 1200 cm^-1 (for a C-F) and 550 cm^-1
(for C-I). So it's not so much as it really helps one way or the
other, but carbon-halogen bonds tend to stretch in the noisier end
of the spectrum, where all the overtones and combinations also
come into play - so clear cut assignment is probably less obvious.

Stephan
--
Stephan Bird MChem(Hons) AMRSC
Currently in Caernarfon, Wales
.