[Avicenna]

Hello, I have been doing a homework on electron transfer. I have come across forster equation several times and have been trying to understand it. One of the problems is that I can't find out what is emission dipole moment and absorption dipole moment (I have come across transition dipole moments several times). What is its difference from dipole moment, is it the dipole moment of the molecules when they are in ground and excited state? Any reference would help too, thanks. (and if you know any thing more about forster equation you are welcome to enlighten me any information will be regarded with appreciation d:)

[tamim83]

Hi,
The magnitude transition dipole moment is a measure of charge redistribution during a transition of some sort.  The difference is just what you said I believe, the transition dipole moment is only observed during a transition and is not perminent.  You usually hear about this in spectroscopy problems.  The transition dipole moment must be nonzero for a transition to be allowed.  In other words, the generation or change in the dipole moment during a transition will result in a spectroscopic transition.  If you are still curious check out Atkins Physical Chemistry 7th edition.