Dear Steven,

Some time ago we wrote the Models360 website:
http://www.chemeddl.org/resources/models360/models.php?pubchem=11638

where you can click on "Molecular Vibrations" --> "View IR spectrum".
If you click on each IR band you can see what normal mode of vibration
it corresponds to. (Note: These are very simplistic approximations to
the IR spectrum)

I'm not aware of any technique that would allow you to calculate "on
the fly" the IR spectrum of a distorted structure and I'm not sure if
that would make any physical sense since the IR spectrum corresponds
to the average of a collection of conformers. For small molecules the
harmonic approximation is good enough for qualitative predictions.
That's what we did in Models360, the IR frequencies come from the
second derivative of the electronic energy.
Or maybe I misinterpreted what you meant by "manipulating structural
features" and you meant changing one atom into another, for example,
observe how IR changes when going from fluoromethane to chloromethane
to methanol. Any sequence can be done provided that the molecule
exists in the collection
Fluromethane
http://www.chemeddl.org/resources/models360/models.php?pubchem=11638
Chloromethane
http://www.chemeddl.org/resources/models360/models.php?pubchem=6327
Methanol
http://www.chemeddl.org/resources/models360/models.php?pubchem=887

One can also obtain the real IR spectra from NIST, which is more
realistic, but then less accessible to first year students.
For chloromethane:
http://webbook.nist.gov/cgi/cbook.cgi?ID=C74873&Units=SI&Mask=80#IR-Spec

If you think it could be useful, I could arrange that IR/Jmol
information in a way that students can compare a specific sequence of
molecules. E-mail me off the list if you are interested.

Xavier

On Mon, Sep 1, 2014 at 9:48 AM, Steven Cullipher
<[log in to unmask]> wrote:
> Dear CER colleagues,
>
> I'm looking for a computer-based interactive simulation that explores the
> relationship between a molecular structure and its IR spectrum. Ideally, I
> want something that is simple enough for a first semester general chemistry
> student to interact with. I'd like the student to be able to build a
> molecule and see its theoretical IR spectrum and then explore how
> manipulating structural features of the molecule alters the spectrum. Does
> anyone know of any software or web-based simulations that fit these
> criteria?
>
> Thanks!
> Steven
>
> --
> Steven Cullipher
> Green Chemistry Ph.D. Student
> Sevian Research Group
> UMass Boston



-- 
Xavier Prat-Resina
Assistant Professor, Chemistry.
University of Minnesota Rochester.
111 South Broadway, Suite 300
Rochester, Minnesota 55904

Phone: 507-258-8215
E-mail: [log in to unmask]
https://sites.google.com/a/r.umn.edu/prat-resina/