Re: [Phys-L] Data discussion and Infinite square well

[Jim Diamond <jiminoregon@gmail.com>]

John and everyone on the list, Happy New Year!

These are UV-Vis spectra.

There is some interesting background.

   - because the pi bond order is reduced upon absorption in the pi->pi*
   transition, there is strong vibronic coupling to the CC stretch vibration,
   which modulates the obsorption spectrum dramatically (see the "boy scout
   salute" passage in the reference below)
   http://www.ks.uiuc.edu/History/polyene/
   - the fluorescing state in longer polyenes is not the absorbing state,
   leading to a gap between absorption and emission. The history of some of
   this regarding the contributions of Klaus Schulten to understanding the
   properties of the fluorescing state is recounted in the above link. This
   also recounts the part of polyene history contributed by Bryan Kohler, who
   die far too early from a brain tumor at the age of 56.
   - There are several versions of experiments floating around the
   internets:
   - Diphenylpolyene Dye Spectra
   https://www.d.umn.edu/~psiders/courses/chem4644/labinstructions/dyespec_tddft.pdf
   - Particle in a Box
   http://www.uta.edu/faculty/bradp/resources/chem3175/3175_PIB_examples.pdf

I hope this information is useful.

The bio sketch of Klaus Schulten includes this nice little joke of which he
was fond that I will pass long.

> An old rabbi is getting ready to retire, so starts to train a young rabbi.
> Sitting in the old rabbi's office one day, conducting their rabbi business,
> there was a knock at the door. A woman appeared and started complaining
> about her husband to the old rabbi. “He is always going to the pub. He
> doesn't help with the children. He is a really bad husband, etc.” The old
> rabbi looked at the woman and said, “You are right, you are right, you are
> so right.” The woman looked satisfied and left the office. Some time later
> another knock came at the door, and this time a man appeared. It was the
> husband of the woman. He started complaining bitterly about his wife. “She
> doesn't know how to cook. She doesn't keep house well. She complains
> bitterly to me, etc.” The old rabbi looked at the man and said, “You are
> right, you are right, you are so totally right.” The man looked happy and
> left the rabbi's office. At this point, the young rabbi turns to the old
> rabbi and says, “Ah, what is this? How can you say that both she is right
> and he is right? That is wrong!” And the old rabbi turns to him and says,
> “You're right.”
Best wishes,
Jim


On Thu, Dec 31, 2015 at 9:00 AM, <phys-l-request@www.phys-l.org> wrote:

> From: John Sohl <jsohl@weber.edu>
> To: phys-l@www.phys-l.org
> Cc:
> Date: Wed, 30 Dec 2015 10:33:10 -0700
> Subject: [Phys-L] Data discussion and Infinite square well
> 1. Data: Thank you John D., much better. I really like a lot of the
> resources you have on your website.
>
> 2. Infinite square well. I don't have that chemistry book. I do have a
> bunch of spectrometers with better than 5nm resolution. I also have easy
> access to those chemicals listed. But, what is the wavelength range? IR,
> Vis, UV?
>
> Thanks,
>
> John
>
> - - - -
> John E. Sohl, Ph.D.
> Professor of Physics
> Weber State University
> 1415 Edvalson St., Dept 2508
> Ogden, UT 84408-2508
>
> voice: (801) 626-7907, fax: (801) 626-7445
> cell: (801) 476-0589