Subject: pre-reaction complexes

From: "Alimet S. Ozen" <[email-masked]>
Date: Thu, 20 Mar 2003 21:40:29 +0200 (EET)

Dear CCL Members,

We are currently performing DFT calculations in order to elucidate the
mechanism of some radical reactions.
There are 6-7 pathways for each substituted molecule and I am just
wondering if it is possible to compare only the
transition states -setting the lowest energy TS as zero and scaling the
others respectively- without having to calculate 
the pre-reaction complexes...(most of the TSs are lower in energy than the
reactants)
... just thinking that any contribution due to a pre-reaction complex
actually cancels out during the calculation of the activation energy
though it is still important in calculating the tunneling
correction...so, comparing only the TSs will at least give some
qualitative info...?
I will be so glad to hear your opinions about it...

Kind Regards
Alimet  

"Real value:is not the one whose presence fills an empty space but
the one whose absence creats one" Ozdemir Asaf
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