[boramhuh]

Hello guys,
I am really embarassed to post this, but it has been three years since I got out of University,
and now I'm trying to study for graduate school.

This is one of the questions that I am faced with, and I tried to look it up in the book and on-line, but I couldn't really find anything
helpful..

I am not expecting straight answers from you.. I just need a starting point or a "hint" where I could obtain info to solve this problem..

Anyways,, here is the problem:

Condier the molecular diagram for pi orbitals of benzene. The gap between the lowest two energy levels is 2.3 eV, while that between the two middle ones is 5.0eV. What should be the wavelength (in nm) of the first optical transition for neutral and cationic benzene? (1 eV= 1240nm)


hMm..
any equations that I could apply or theory that I need to know...?

Any help would be appreciated.

Thank you in advance!