> Its been awhile since Pchem, but does anyone know if microwave radiation
> can "e*" or be absorbed by specific atoms in a macromolecule?
> similar to NMR, albeit without the signal emission, so that the energy is
> absorbed by the atom? I know they use microwave radiation to do
> spectroscopy on determing the moments of inertia of small gas molecules,
> but would be interested if microwave radiation could be 'tuned' as it
> were to specific frequencies to e* atoms in a larger molecule...I
> understand this would be vibrational energy levels and they are not as
> distinct as other energy quanta...but any thoughts would be appreciated..
> it is just something I have been wondering about. thanks Tim
Hertzberg, a Canadian with the Research Council of Canada, during WWII.
It's a 2-volume set. Volume I is on diatomic molecules -- I have the 2nd
edition, republished in 1950 by Van Nostrand Reinhold (no ISBN available).
Volume II is "Infrared and Raman Spectra of Polyatomic Molecules" I have
never actually seen a copy, but know at least one physicist who says he
has one, and says it's terrific. Apparently the treatment is timeless...
Basically, electron-orbital transitions are e*d by near-IR through
far-UV energy quanta (photons are reputed to do nicely). Vibrational
spectra (both compressive/tensile, and torsional rotation of double-bond
structures) are typically in the mid- to near-IR range, and rotational
of single-bond structures are in the microwave to far-IR range, at least
for diatomic molecules. The same rules of thumb probably apply loosely
to polyatomic molecules; Hertzberg's second volume probably names names
and gives numbers. The technology of efficient excitation (required for
hassle-free storage) and saturation limits (joules/mole before the wheels
start coming off chemically) are another matter about which I know nearly
nothing. Happy reading!